{"id":74443,"date":"2026-10-29T12:41:51","date_gmt":"2026-10-29T19:41:51","guid":{"rendered":"https:\/\/cirasync.com\/?p=74443"},"modified":"2026-10-29T12:41:51","modified_gmt":"2026-10-29T19:41:51","slug":"microsoft-365-contact-sync-mergers-acquisitions","status":"publish","type":"post","link":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/","title":{"rendered":"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0"},"content":{"rendered":"<p><span data-contrast=\"none\">After a merger or acquisition, organizations often operate multiple Microsoft 365 tenants while integrating their people, systems and directories. During this coexistence period, employees need to find colleagues across company boundaries, even when their accounts remain in separate tenants. Microsoft Entra cross-tenant synchronization can provision users into another tenant and support GAL visibility when the required address-list attributes and Exchange recipient settings are correctly configured. However, making employees searchable in Outlook does not automatically synchronize their contact information to smartphones.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">That split matters because a newly combined company rarely runs on one tenant from day one. Domains, mailboxes and identities usually stay in separate tenants for months while the integration team plans consolidation. During that time, employees expect to find their new colleagues in Outlook, Teams and their phone&#8217;s Contacts app as if they already worked for one company.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">This guide explains why GALs do not merge on their own, what Microsoft&#8217;s native tools do and do not cover, the decisions to make before you sync anything, and a phased approach from day one through consolidation.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h2 aria-level=\"2\"><span class=\"ez-toc-section\" id=\"Key_takeaways\"><\/span>Key takeaways<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335559738&quot;:280,&quot;335559739&quot;:100}\">\u00a0<\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><b><span data-contrast=\"none\">Microsoft now offers native cross-tenant user sync.<\/span><\/b><span data-contrast=\"none\"> Cross-tenant synchronization can make synced users discoverable in the target tenant&#8217;s GAL, and it underpins Microsoft 365 multitenant organizations.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><b><span data-contrast=\"none\">It syncs users and security groups, not contacts.<\/span><\/b><span data-contrast=\"none\"> Microsoft states that contacts and devices are not supported, and distribution lists are not created in the target tenant.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><b><span data-contrast=\"none\">A searchable GAL is not a phone directory.<\/span><\/b><span data-contrast=\"none\"> Synced colleagues can be found in Outlook, but they do not appear by name on incoming calls unless they are delivered to the phone&#8217;s contacts.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><b><span data-contrast=\"none\">Pre-close sync needs a legal check.<\/span><\/b><span data-contrast=\"none\"> Microsoft intends cross-tenant synchronization for use within one organization and notes extra compliance duties, including GDPR, when it is used across organizations.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><b><span data-contrast=\"none\">Plan for three phases.<\/span><\/b><span data-contrast=\"none\"> Day one, coexistence and consolidation each need a different contact strategy.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/li>\n<\/ul>\n<h2 aria-level=\"2\"><span class=\"ez-toc-section\" id=\"Why_GALs_do_not_merge_on_their_own_after_an_acquisition\"><\/span>Why GALs do not merge on their own after an acquisition<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span data-contrast=\"none\">Each Microsoft 365 tenant has its own Microsoft Entra directory and its own Exchange Online GAL. Nothing in one tenant appears in another unless someone puts it there. Three constraints keep the tenants apart longer than most business leaders expect.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<ul>\n<li><b><span data-contrast=\"none\">A domain belongs to one tenant at a time.<\/span><\/b><span data-contrast=\"none\"> Microsoft&#8217;s cross-tenant migration guidance states that domains are associated with only one Microsoft Entra ID or Exchange Online tenant (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/microsoft-365\/migration\/cross-tenant-mailbox-migration?view=o365-worldwide\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">). The acquired company&#8217;s email domain cannot move until its mailboxes are ready to move with it.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><b><span data-contrast=\"none\">Consolidation is a project, not a switch.<\/span><\/b><span data-contrast=\"none\"> Mailbox moves require licensing, identity preparation and batch planning, so many organizations run two or more tenants side by side for months.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><b><span data-contrast=\"none\">Some organizations never consolidate.<\/span><\/b><span data-contrast=\"none\"> Regulatory separation, regional data requirements or a planned divestiture can make a long-term multi-tenant setup the intended end state.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/li>\n<\/ul>\n<p><span data-contrast=\"none\">During that coexistence period, the GAL is the first place people notice the gap. A sales rep cannot find the acquired company&#8217;s account manager in Outlook, a new manager cannot address their team, and calls from colleagues arrive as unknown numbers.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h2 aria-level=\"2\"><span class=\"ez-toc-section\" id=\"Microsofts_native_options_for_cross-tenant_GALs\"><\/span>Microsoft&#8217;s native options for cross-tenant GALs<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span data-contrast=\"none\">Microsoft offers three native building blocks. They solve different parts of the problem and are often combined.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Microsoft_Entra_cross-tenant_synchronization\"><\/span>Microsoft Entra cross-tenant synchronization<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Microsoft Entra cross-tenant synchronization provisions supported B2B collaboration users from a source tenant into a target tenant. In March 2026, Microsoft introduced cross-tenant security-group synchronization in preview for supported same-cloud environments. This functionality supports eligible security groups but does not create distribution lists, mail-enabled security groups or Microsoft 365 groups in the target tenant. Microsoft documents the following capabilities and requirements:<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<ul>\n<li><span data-contrast=\"none\">It is a push from the source tenant, where admins choose the users in scope and the attribute mappings.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><span data-contrast=\"none\">It syncs only internal members of the source tenant, not that tenant&#8217;s own external users.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><span data-contrast=\"none\">It runs on a fixed cycle that starts every 40 minutes, with a longer first run.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><span data-contrast=\"none\">It can enable people search in Microsoft 365. The showInAddressList attribute is set to True by default in the attribute mappings.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<li><span data-contrast=\"none\">Each synced user needs a Microsoft Entra ID P1 license in the source tenant.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/li>\n<\/ul>\n<p><span data-contrast=\"none\">Once users are synced, Microsoft says people in the target tenant can find them in Outlook search and the To line, and open a people card (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/microsoft-365\/enterprise\/multi-tenant-people-search?view=o365-worldwide\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">). Since late 2025, users hidden from the GAL in the source tenant also stay hidden in the target (<\/span><a href=\"https:\/\/mc.merill.net\/message\/MC1187400\"><span data-contrast=\"none\">Microsoft message center, MC1187400<\/span><\/a><span data-contrast=\"none\">).<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Microsoft_365_multitenant_organization\"><\/span>Microsoft 365 multitenant organization<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">A multitenant organization groups the tenants your company owns into one boundary, with improved collaboration in Teams and Viva Engage (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/entra\/identity\/multi-tenant-organizations\/multi-tenant-organization-overview\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">). It relies on provisioning member users across tenants, typically through cross-tenant synchronization. Microsoft 365 multitenant organizations support up to 100 tenants in the standard configuration, and each tenant can belong to only one multitenant organization. Microsoft Entra ID P1 or higher licensing is required in participating tenants. Cross-tenant user synchronization requires an Entra ID P1 license for each synchronized user in the source tenant, while group synchronization has additional licensing requirements. Administrators should verify licensing and supported tenant configurations before implementation.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Mail_contacts_traditional_GAL_sync\"><\/span>Mail contacts (traditional GAL sync)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">The older approach represents users from another tenant as mail contacts. Microsoft&#8217;s Entra architecture guidance explains the trade-offs (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/entra\/architecture\/multi-tenant-common-considerations\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">):<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<ul>\n<li><span data-contrast=\"auto\">Mail contacts appear in the GAL without granting access, because they are not security principals.<\/span><span data-ccp-props=\"{}\">\u00a0<\/span><\/li>\n<li><span data-contrast=\"auto\">Microsoft Graph has no API for managing Exchange mail contacts, so admins need Exchange Online PowerShell or the Exchange admin center to create and manage them.<\/span><span data-ccp-props=\"{}\">\u00a0<\/span><\/li>\n<li><span data-contrast=\"auto\">A mail contact and a mail-enabled external user cannot exist in the same tenant with the same email address.<\/span><span data-ccp-props=\"{}\">\u00a0<\/span><\/li>\n<\/ul>\n<h2 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"How_the_options_compare\"><\/span>How the options compare<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<table data-tablestyle=\"MsoNormalTable\" data-tablelook=\"1696\" aria-rowcount=\"7\" aria-colcount=\"4\">\n<tbody>\n<tr aria-rowindex=\"1\">\n<td data-celllook=\"69905\"><span data-contrast=\"none\">Capability<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:2,&quot;335551620&quot;:2,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"69905\"><span data-contrast=\"none\">Cross-tenant synchronization<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:2,&quot;335551620&quot;:2,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"69905\"><span data-contrast=\"none\">Multitenant organization<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:2,&quot;335551620&quot;:2,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"69905\"><span data-contrast=\"none\">Mail contacts<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:2,&quot;335551620&quot;:2,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"2\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">What it creates<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">B2B users and security groups<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Tenant group that uses B2B member users<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Contact objects in the GAL<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"3\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Appears in the GAL<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Yes, when showInAddressList is True<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Yes, through synced member users<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Yes<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"4\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Enables cross-tenant resource access<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Provisions B2B identities that can be granted access according to applicable policies and permissions<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Supports collaboration through provisioned B2B users and configured access policies<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">No, mail contacts are not sign-in identities<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"5\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Syncs external contacts and distribution lists<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">No<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">No<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Must be created separately<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"6\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Puts colleagues in phone contacts<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">No<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">No<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">No<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"7\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Licensing noted by Microsoft<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Entra ID P1 per synced user in the source<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Entra ID P1<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">None stated<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:-108,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span data-contrast=\"none\">Microsoft recommends B2B collaboration rather than traditional GAL synchronization for representing users who need to appear in the GAL. Mail contacts remain useful for directory-only visibility and for external contacts that cross-tenant sync does not cover.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h2 aria-level=\"2\"><span class=\"ez-toc-section\" id=\"What_native_cross-tenant_sync_does_not_solve\"><\/span>What native cross-tenant sync does not solve<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span data-contrast=\"none\">When configured correctly, cross-tenant synchronization can make users from another tenant discoverable in Microsoft 365. However, identity provisioning does not automatically guarantee GAL visibility or synchronize contacts to employee phones. Six gaps usually remain for M&amp;A teams.<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Phones_still_show_unknown_numbers\"><\/span>Phones still show unknown numbers<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">A user who is searchable in the GAL is not a saved contact on anyone&#8217;s phone. Outlook and an iPhone&#8217;s Exchange account can look the person up, but the phone&#8217;s Contacts app, which drives caller ID, only shows contacts synced to it. For the people who call each other across the two companies, the directory still has to be delivered to their phones. Our <\/span><a href=\"https:\/\/cirasync.com\/blog-articles\/gal-sync-guide\/\"><span data-contrast=\"none\">GAL sync guide<\/span><\/a><span data-contrast=\"none\"> explains this directory-to-phone gap.<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"External_contacts_and_distribution_lists_stay_behind\"><\/span>External contacts and distribution lists stay behind<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Microsoft states that cross-tenant synchronization supports users and security groups, while devices and contacts are not supported. It does not create distribution groups, mail-enabled security groups or Microsoft 365 groups in the target tenant (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/entra\/identity\/multi-tenant-organizations\/cross-tenant-synchronization-overview\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">). Vendor, partner and customer contacts in either company&#8217;s GAL need a separate plan.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Profiles_are_thinner_than_in_the_home_tenant\"><\/span>Profiles are thinner than in the home tenant<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><a href=\"https:\/\/learn.microsoft.com\/en-us\/entra\/identity\/multi-tenant-organizations\/cross-tenant-synchronization-overview?utm_source=chatgpt.com\"><span data-contrast=\"none\">Microsoft Entra cross-tenant synchronization<\/span><\/a><span data-contrast=\"none\"> does not support synchronizing user profile photos between tenants. As a result, synchronized users may appear without their profile pictures in Microsoft 365 people-search experiences unless those photos are provided through another supported method. Other profile information available in the target tenant depends on the attributes synchronized and the Microsoft 365 application being used.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Conflicts_between_mail_contacts_and_synced_users\"><\/span>Conflicts between mail contacts and synced users<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">If a GAL sync tool has already created mail contacts for the other company&#8217;s employees, those records collide with cross-tenant sync. Microsoft notes that a mail contact and a mail-enabled external user cannot share an email address in the same tenant, and inviting a B2B member when a matching mail contact exists returns a proxy address conflict (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/entra\/architecture\/multi-tenant-common-considerations\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">). Decide which mechanism represents each person before turning either one on.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Hybrid_tenants_may_not_see_the_same_GAL_on-premises\"><\/span>Hybrid tenants may not see the same GAL on-premises<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Microsoft lists write-back to on-premises Windows Server Active Directory as something cross-tenant sync does not provide. If the target company still hosts mailboxes on Exchange Server, users there may not see the synced colleagues that cloud mailboxes see.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Pre-close_sharing_needs_legal_review\"><\/span>Pre-close sharing needs legal review<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Microsoft says cross-tenant synchronization is intended for use within an organization. Using it across organizations can add compliance responsibilities, including under the GDPR, and Microsoft advises consulting legal or compliance teams first. Before a deal closes, the two companies are still separate organizations, so get sign-off on what directory data can be shared and with whom.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h2 aria-level=\"2\"><span class=\"ez-toc-section\" id=\"Decisions_to_make_before_unifying_GALs\"><\/span>Decisions to make before unifying GALs<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335559738&quot;:280,&quot;335559739&quot;:100}\">\u00a0<\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span data-contrast=\"none\">Settle these eight questions with HR, legal and both IT teams before syncing anything. Changing them later means cleaning up thousands of directory objects.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Before enabling cross-tenant synchronization or a GAL-to-GAL synchronization tool, audit the target tenant for existing mail contacts, B2B users and duplicate email addresses. Confirm which system will manage each object type. Conflicting objects can cause provisioning failures, duplicate directory entries or unexpected changes to address list visibility. Test the synchronization configuration with a limited group before expanding it across the organization.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Important deprovisioning consideration: Removing users from cross-tenant synchronization scope can trigger soft deletion of their corresponding target tenant objects when deletion actions are enabled. Before changing synchronization scope, IT teams should verify object dependencies, review the provisioning configuration and coordinate with the identity and migration teams to prevent unintended account disruption.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<table data-tablestyle=\"MsoNormalTable\" data-tablelook=\"1696\" aria-rowcount=\"9\" aria-colcount=\"3\">\n<tbody>\n<tr aria-rowindex=\"1\">\n<td data-celllook=\"69905\"><b><span data-contrast=\"none\">Decision<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:2,&quot;335551620&quot;:2,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"69905\"><b><span data-contrast=\"none\">Questions to answer<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:2,&quot;335551620&quot;:2,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"69905\"><b><span data-contrast=\"none\">Why it matters<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:2,&quot;335551620&quot;:2,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"2\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Scope<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Which employees from each company should appear in the other GAL? All staff, or only certain departments?<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Cross-tenant sync and GAL sync tools both work from a defined scope. Too broad exposes data; too narrow frustrates users.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"3\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Direction<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">One-way from the acquired company into the parent, or both ways?<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Cross-tenant sync runs one direction per configuration, so mutual visibility needs one job in each direction.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"4\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Object types<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Users only, or also shared mailboxes, rooms, external contacts and distribution lists?<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Native user sync does not cover contacts or distribution lists.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"5\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Source of authority<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Which tenant owns each person&#8217;s attributes during coexistence?<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Microsoft treats the source tenant as authoritative; edits in the target are overwritten when the source changes.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"6\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Naming<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Will display names show the company, for example a suffix or the company attribute?<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Two people with the same name in a merged GAL cause misaddressed email.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"7\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Representation<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Will each person appear as a synced B2B user or as a mail contact?<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">The two cannot share an email address in the same tenant.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"8\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Phones<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Which teams need the other company&#8217;s people as phone contacts?<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">GAL visibility alone does not provide caller ID.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<tr aria-rowindex=\"9\">\n<td data-celllook=\"4369\"><span data-contrast=\"none\">End state<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">Consolidate into one tenant, or stay multi-tenant long term?<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<td data-celllook=\"4369\"><span data-contrast=\"none\">This decides whether sync is temporary scaffolding or permanent infrastructure.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:102,&quot;335559737&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span data-contrast=\"none\">The source-of-authority point comes from Microsoft&#8217;s FAQ: cross-tenant synchronization treats the source tenant&#8217;s values as authoritative, and changes made in the target persist only until the user changes in the source (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/entra\/identity\/multi-tenant-organizations\/cross-tenant-synchronization-overview\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">).<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h2 aria-level=\"2\"><span class=\"ez-toc-section\" id=\"A_phased_approach_from_deal_close_to_consolidation\"><\/span>A phased approach: from deal close to consolidation<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span data-contrast=\"none\">Each phase of an integration needs a different contact strategy. Work through them in order.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Phase_1_Before_the_deal_closes\"><\/span>Phase 1: Before the deal closes<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Get legal and compliance approval for any directory data shared between the companies.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Inventory each tenant: user counts, mail contacts, distribution lists, shared mailboxes, rooms and any existing GAL sync tools.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Check Microsoft Entra ID P1 licensing for users you plan to sync.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Agree on the decisions in the table above.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Phase_2_Day_one\"><\/span>Phase 2: Day one<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335559738&quot;:240,&quot;335559739&quot;:80}\">\u00a0<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Turn on cross-tenant synchronization for the users who need to find each other first, typically leadership, sales, finance and IT.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Confirm showInAddressList is set so synced users appear in each GAL.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Push a short list of essential contacts to employees&#8217; phones, such as executives, help desks and key site contacts, so calls show names from the first week.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Phase_3_Coexistence\"><\/span>Phase 3: Coexistence<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Expand the sync scope in batches and monitor provisioning logs.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Create mail contacts or distribution lists that cross-tenant sync does not cover, avoiding duplicates of synced users.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Deliver the combined directory to phones for the teams that call across companies.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">If the companies plan to stay separate long term, consider a multitenant organization for the Teams and Viva Engage experience.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Phase_4_Consolidation\"><\/span>Phase 4: Consolidation<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Plan mailbox consolidation using a supported migration method, such as Microsoft&#8217;s cross-tenant mailbox migration capability, where the environment meets its prerequisites. This process is separate from Microsoft Entra cross-tenant synchronization and requires additional planning for licensing, target identities, mailbox attributes, migration batches and domain cutover. Validate the migration method and its limitations before moving production mailboxes. Microsoft notes that cross-tenant synchronization is not a migration tool, because synced users still authenticate in their source tenant.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Pre-create external contacts and distribution lists in the target tenant, as Microsoft&#8217;s FastTrack guidance requires (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/microsoft-365\/fasttrack\/cross-tenant-migration\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">).<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Before removing migrated users from cross-tenant synchronization, verify how their target tenant identities and mailbox objects will be managed after migration. Removing a user from synchronization scope can trigger soft deletion of the corresponding target object, depending on the provisioning configuration. Coordinate identity cutover, mailbox migration and synchronization deprovisioning, and test the process before applying it to production users.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Clean up the source tenant. Microsoft notes the source mailbox becomes a mail user after migration, which can later be removed or converted to a mail contact (<\/span><a href=\"https:\/\/learn.microsoft.com\/en-us\/microsoft-365\/migration\/cross-tenant-mailbox-migration?view=o365-worldwide\"><span data-contrast=\"none\">Microsoft Learn<\/span><\/a><span data-contrast=\"none\">).<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">Rebuild phone contact delivery for migrated users, since their mail accounts and contact sources change.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h2 aria-level=\"2\"><span class=\"ez-toc-section\" id=\"How_CiraSync_supports_multi-tenant_contact_sync\"><\/span>How CiraSync supports multi-tenant contact sync<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335559738&quot;:280,&quot;335559739&quot;:100}\">\u00a0<\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span data-contrast=\"none\">CiraSync and CiraHub support different parts of enterprise contact synchronization. CiraHub provides multi-way synchronization between connected directories and other supported contact sources, while CiraSync helps deliver company contacts to supported employee devices. Together, these capabilities can help IT teams maintain contact availability across multiple Microsoft 365 tenants during mergers, acquisitions and ongoing coexistence.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"none\">Unifying company directories during M&amp;A with CiraHub<\/span><\/b><span data-contrast=\"none\">. When two organizations operate separate Microsoft 365 tenants, CiraHub can synchronize supported contact information between connected directories. IT teams can configure mappings, filters and synchronization rules to manage which contact records are shared across the organizations during coexistence.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"none\">Maintaining consistent contact information across tenants<\/span><\/b><span data-contrast=\"none\">. During a merger, employee details, phone numbers and organizational information may change frequently. CiraHub&#8217;s multi-way synchronization capabilities help keep supported contact records aligned across connected systems, reducing the need for manual directory updates while the tenants remain separate.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"none\">Making cross-company contacts available on employee phones.<\/span><\/b><span data-contrast=\"none\"> Once the relevant contact information is available, CiraSync Cloud can synchronize selected company contacts into targeted Microsoft 365 mailbox Contacts folders. For supported managed-device environments, Mobile Direct provides an alternative CardDAV-based delivery method. This helps employees access colleagues&#8217; contact details on their smartphones even while the organizations continue operating separate tenants.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559685&quot;:720,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">If you also run Microsoft Entra cross-tenant synchronization, decide which tool represents each person in each GAL, so the same employee is not created twice.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"none\">In a published example, a $100B+ alternative investment firm with more than 2,000 employees across two dozen offices needed corporate contacts to reach a mailbox in a second Microsoft 365 tenant. CiraSync reports that multi-way sync was live within weeks, without custom engineering (<\/span><a href=\"https:\/\/cirasync.com\/case-studies\/cross-tenant-contact-sync-microsoft-365\/\"><span data-contrast=\"none\">case study<\/span><\/a><span data-contrast=\"none\">).<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h2 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Plan_your_multi-tenant_directory\"><\/span>Plan your multi-tenant directory<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><span data-contrast=\"none\">If you are preparing for a close or already running two tenants, <\/span><a href=\"https:\/\/cirasync.com\/cira-platform-demo\/\"><span data-contrast=\"none\">talk to a CiraSync specialist<\/span><\/a><span data-contrast=\"none\"> about scoping GAL sync and phone contacts for each phase, or <\/span><a href=\"https:\/\/cirasync.com\/get-cirasync-enterprise-edition\/\"><span data-contrast=\"none\">start a free trial<\/span><\/a><span data-contrast=\"none\"> with a pilot group.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h2 aria-level=\"2\"><span class=\"ez-toc-section\" id=\"Frequently_asked_questions\"><\/span>Frequently asked questions<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335559738&quot;:280,&quot;335559739&quot;:100}\">\u00a0<\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Can_Microsoft_365_sync_the_GAL_between_two_tenants_natively\"><\/span>Can Microsoft 365 sync the GAL between two tenants natively?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Partly. Microsoft Entra cross-tenant synchronization can provision users from one tenant into another and make them discoverable in the target tenant&#8217;s GAL. It does not sync contacts or create distribution lists, so those still need a separate process.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"What_is_the_difference_between_cross-tenant_synchronization_and_a_multitenant_organization\"><\/span>What is the difference between cross-tenant synchronization and a multitenant organization?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Cross-tenant synchronization is the engine that provisions users and security groups between a source and a target tenant. A multitenant organization is a grouping of tenants your company owns, which improves Teams and Viva Engage collaboration and typically relies on cross-tenant synchronization to provision member users.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Does_cross-tenant_synchronization_put_contacts_on_employees_phones\"><\/span>Does cross-tenant synchronization put contacts on employees&#8217; phones?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">No. It creates B2B users in the target directory, which Outlook can search. Phones show names on incoming calls only for contacts synced to the device, so the directory still has to be delivered to phones.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"How_often_does_cross-tenant_synchronization_update\"><\/span>How often does cross-tenant synchronization update?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Microsoft says the sync interval is fixed to start every 40 minutes. The first cycle takes longer, depending on how many users are in scope.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Can_we_sync_GALs_before_the_acquisition_closes\"><\/span>Can we sync GALs before the acquisition closes?<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335559738&quot;:240,&quot;335559739&quot;:80}\">\u00a0<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">It is technically possible, but Microsoft intends cross-tenant synchronization for use within an organization and notes added compliance responsibilities, including GDPR, when used across organizations. Get legal approval before sharing directory data with a company you do not yet own.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Should_we_use_mail_contacts_or_synced_users\"><\/span>Should we use mail contacts or synced users?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">Use synced users when people need access to resources in the other tenant. Mail contacts suit directory-only visibility and external contacts. Avoid both for the same person, because Microsoft notes a mail contact and a mail-enabled external user cannot share an email address in one tenant.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"Is_cross-tenant_synchronization_a_migration_tool\"><\/span>Is cross-tenant synchronization a migration tool?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">No. Microsoft states that synced users still authenticate in their source tenant, and that tenant migrations also require moving data. Use cross-tenant mailbox migration for consolidation.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n<h3 aria-level=\"3\"><span class=\"ez-toc-section\" id=\"What_licenses_does_cross-tenant_synchronization_need\"><\/span>What licenses does cross-tenant synchronization need?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><span data-contrast=\"none\">For cross-tenant user synchronization within the same Microsoft cloud, each synchronized user requires a Microsoft Entra ID P1 license in the source tenant. Synchronizing security groups requires Microsoft Entra ID Governance or Microsoft Entra Suite licensing. Cross-cloud synchronization also requires Microsoft Entra ID Governance or Microsoft Entra Suite licensing. Target tenant licenses are not required specifically for the synchronization process, although additional licenses may be needed for other Microsoft 365 services or features.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:160}\">\u00a0<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>After a merger or acquisition, organizations often operate multiple Microsoft 365 tenants while integrating their people, systems and directories. During this coexistence period, employees need to find colleagues across company boundaries, even when their accounts remain in separate tenants. Microsoft Entra cross-tenant synchronization can provision users into another tenant and support GAL visibility when the [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":46654,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","_nextfly_llmd_date_locked":false,"footnotes":"","_ppma_block_editor_authors":"","_links_to":"","_links_to_target":""},"categories":[1478,13550],"tags":[28,13623,13665],"ppma_author":[13546],"class_list":["post-74443","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog-articles","category-featured-articles","tag-cirasync","tag-financial-services","tag-mergers-acquisitions","rawdate-2026-10-29"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v28.7 (Yoast SEO v28.7) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0 &#8212; CiraSync<\/title>\n<meta name=\"description\" content=\"Cross-tenant sync makes colleagues searchable in the GAL but does not reach phones. See how IT unifies M&amp;A contacts across tenants with CiraSync\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/\/\" \/>\n<meta property=\"og:locale\" content=\"es_ES\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0\" \/>\n<meta property=\"og:description\" content=\"Cross-tenant sync makes colleagues searchable in the GAL but does not reach phones. See how IT unifies M&amp;A contacts across tenants with CiraSync\" \/>\n<meta property=\"og:url\" content=\"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/\" \/>\n<meta property=\"og:site_name\" content=\"CiraSync\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/CiraSync\/\" \/>\n<meta property=\"article:published_time\" content=\"2026-10-29T19:41:51+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/cirasync.com\/wp-content\/uploads\/2019\/04\/Cirasync_share_1200x630-01.png\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"630\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"Ema Zulic\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@CiraSync\" \/>\n<meta name=\"twitter:site\" content=\"@CiraSync\" \/>\n<meta name=\"twitter:label1\" content=\"Escrito por\" \/>\n\t<meta name=\"twitter:data1\" content=\"Ema Zulic\" \/>\n\t<meta name=\"twitter:label2\" content=\"Tiempo de lectura\" \/>\n\t<meta name=\"twitter:data2\" content=\"14 minutos\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/\"},\"author\":{\"name\":\"Ema Zulic\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#\\\/schema\\\/person\\\/a179dfe101e83de2d1e79161e39e58d0\"},\"headline\":\"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0\",\"datePublished\":\"2026-10-29T19:41:51+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/\"},\"wordCount\":3025,\"publisher\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2024\\\/05\\\/CiraSync-Blog-1080x630-Light.jpg\",\"keywords\":[\"CiraSync\",\"Financial Services\",\"Mergers &amp; Acquisitions\"],\"articleSection\":[\"Blog Articles\",\"Featured\"],\"inLanguage\":\"es\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/\",\"url\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/\",\"name\":\"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0 &#8212; CiraSync\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2024\\\/05\\\/CiraSync-Blog-1080x630-Light.jpg\",\"datePublished\":\"2026-10-29T19:41:51+00:00\",\"description\":\"Cross-tenant sync makes colleagues searchable in the GAL but does not reach phones. See how IT unifies M&A contacts across tenants with CiraSync\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/#breadcrumb\"},\"inLanguage\":\"es\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"es\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/#primaryimage\",\"url\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2024\\\/05\\\/CiraSync-Blog-1080x630-Light.jpg\",\"contentUrl\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2024\\\/05\\\/CiraSync-Blog-1080x630-Light.jpg\",\"width\":1080,\"height\":630,\"caption\":\"Calendar event details showing an attendee who has not responded to the meeting invitation\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/blog-articles\\\/microsoft-365-contact-sync-mergers-acquisitions\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/cirasync.com\\\/es\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#website\",\"url\":\"https:\\\/\\\/cirasync.com\\\/es\\\/\",\"name\":\"CiraSync\",\"description\":\"Sync the Office 365 GAL, public folders and calendars to smartphones.\",\"publisher\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/cirasync.com\\\/es\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"es\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#organization\",\"name\":\"CiraSync\",\"url\":\"https:\\\/\\\/cirasync.com\\\/es\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"es\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2019\\\/07\\\/CiraSync-Logo-.png\",\"contentUrl\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2019\\\/07\\\/CiraSync-Logo-.png\",\"width\":1200,\"height\":671,\"caption\":\"CiraSync\"},\"image\":{\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/CiraSync\\\/\",\"https:\\\/\\\/x.com\\\/CiraSync\",\"https:\\\/\\\/www.linkedin.com\\\/company\\\/cira-apps-limited\",\"https:\\\/\\\/www.youtube.com\\\/channel\\\/UCdFkOfXlRAWRadzGit3jJZA\\\/videos\"],\"description\":\"CiraSync automatically syncs CRM, contact & calendar data from M365, Exchange & many CRMs to every smartphone.\",\"email\":\"support@cirasync.com\",\"telephone\":\"1 (202) 747 0888\",\"legalName\":\"CiraSync\"},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/es\\\/#\\\/schema\\\/person\\\/a179dfe101e83de2d1e79161e39e58d0\",\"name\":\"Ema Zulic\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"es\",\"@id\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2026\\\/01\\\/Ema-Zulic.jpg6908e25f5b970f7afc565f7c922b5564\",\"url\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2026\\\/01\\\/Ema-Zulic.jpg\",\"contentUrl\":\"https:\\\/\\\/cirasync.com\\\/wp-content\\\/uploads\\\/2026\\\/01\\\/Ema-Zulic.jpg\",\"caption\":\"Ema Zulic\"},\"description\":\"Ema Zulic is the Vice President of Product Management and Customer Support at Cira Apps Ltd, where she drives product strategy, customer experience, and global support operations. With over 10 years of SaaS support expertise and more than 20 years of overall customer support leadership, Ema is blending deep technical insight with a passion for building high\u2011performing, customer\u2011centric teams. Her work focuses on delivering intuitive products, refining support processes, and creating seamless experiences for enterprise organizations. Outside of her leadership role, Ema shares practical, real\u2011world guidance to help companies strengthen their support models, improve operational efficiency, and elevate the customer journey.\",\"url\":\"https:\\\/\\\/cirasync.com\\\/es\\\/author\\\/ema-zulic\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0 &#8212; CiraSync","description":"Cross-tenant sync makes colleagues searchable in the GAL but does not reach phones. See how IT unifies M&A contacts across tenants with CiraSync","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/\/","og_locale":"es_ES","og_type":"article","og_title":"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0","og_description":"Cross-tenant sync makes colleagues searchable in the GAL but does not reach phones. See how IT unifies M&A contacts across tenants with CiraSync","og_url":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/","og_site_name":"CiraSync","article_publisher":"https:\/\/www.facebook.com\/CiraSync\/","article_published_time":"2026-10-29T19:41:51+00:00","og_image":[{"width":1200,"height":630,"url":"https:\/\/cirasync.com\/wp-content\/uploads\/2019\/04\/Cirasync_share_1200x630-01.png","type":"image\/png"}],"author":"Ema Zulic","twitter_card":"summary_large_image","twitter_creator":"@CiraSync","twitter_site":"@CiraSync","twitter_misc":{"Escrito por":"Ema Zulic","Tiempo de lectura":"14 minutos"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/#article","isPartOf":{"@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/"},"author":{"name":"Ema Zulic","@id":"https:\/\/cirasync.com\/es\/#\/schema\/person\/a179dfe101e83de2d1e79161e39e58d0"},"headline":"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0","datePublished":"2026-10-29T19:41:51+00:00","mainEntityOfPage":{"@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/"},"wordCount":3025,"publisher":{"@id":"https:\/\/cirasync.com\/es\/#organization"},"image":{"@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/#primaryimage"},"thumbnailUrl":"https:\/\/cirasync.com\/wp-content\/uploads\/2024\/05\/CiraSync-Blog-1080x630-Light.jpg","keywords":["CiraSync","Financial Services","Mergers &amp; Acquisitions"],"articleSection":["Blog Articles","Featured"],"inLanguage":"es"},{"@type":"WebPage","@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/","url":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/","name":"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0 &#8212; CiraSync","isPartOf":{"@id":"https:\/\/cirasync.com\/es\/#website"},"primaryImageOfPage":{"@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/#primaryimage"},"image":{"@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/#primaryimage"},"thumbnailUrl":"https:\/\/cirasync.com\/wp-content\/uploads\/2024\/05\/CiraSync-Blog-1080x630-Light.jpg","datePublished":"2026-10-29T19:41:51+00:00","description":"Cross-tenant sync makes colleagues searchable in the GAL but does not reach phones. See how IT unifies M&A contacts across tenants with CiraSync","breadcrumb":{"@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/#breadcrumb"},"inLanguage":"es","potentialAction":[{"@type":"ReadAction","target":["https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/"]}]},{"@type":"ImageObject","inLanguage":"es","@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/#primaryimage","url":"https:\/\/cirasync.com\/wp-content\/uploads\/2024\/05\/CiraSync-Blog-1080x630-Light.jpg","contentUrl":"https:\/\/cirasync.com\/wp-content\/uploads\/2024\/05\/CiraSync-Blog-1080x630-Light.jpg","width":1080,"height":630,"caption":"Calendar event details showing an attendee who has not responded to the meeting invitation"},{"@type":"BreadcrumbList","@id":"https:\/\/cirasync.com\/es\/blog-articles\/microsoft-365-contact-sync-mergers-acquisitions\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/cirasync.com\/es\/"},{"@type":"ListItem","position":2,"name":"Microsoft 365 Contact Sync for Mergers and Acquisitions: Unifying GALs Across Multiple Tenants\u00a0"}]},{"@type":"WebSite","@id":"https:\/\/cirasync.com\/es\/#website","url":"https:\/\/cirasync.com\/es\/","name":"CiraSync","description":"Sync the Office 365 GAL, public folders and calendars to smartphones.","publisher":{"@id":"https:\/\/cirasync.com\/es\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/cirasync.com\/es\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"es"},{"@type":"Organization","@id":"https:\/\/cirasync.com\/es\/#organization","name":"CiraSync","url":"https:\/\/cirasync.com\/es\/","logo":{"@type":"ImageObject","inLanguage":"es","@id":"https:\/\/cirasync.com\/es\/#\/schema\/logo\/image\/","url":"https:\/\/cirasync.com\/wp-content\/uploads\/2019\/07\/CiraSync-Logo-.png","contentUrl":"https:\/\/cirasync.com\/wp-content\/uploads\/2019\/07\/CiraSync-Logo-.png","width":1200,"height":671,"caption":"CiraSync"},"image":{"@id":"https:\/\/cirasync.com\/es\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/CiraSync\/","https:\/\/x.com\/CiraSync","https:\/\/www.linkedin.com\/company\/cira-apps-limited","https:\/\/www.youtube.com\/channel\/UCdFkOfXlRAWRadzGit3jJZA\/videos"],"description":"CiraSync automatically syncs CRM, contact & calendar data from M365, Exchange & many CRMs to every smartphone.","email":"support@cirasync.com","telephone":"1 (202) 747 0888","legalName":"CiraSync"},{"@type":"Person","@id":"https:\/\/cirasync.com\/es\/#\/schema\/person\/a179dfe101e83de2d1e79161e39e58d0","name":"Ema Zulic","image":{"@type":"ImageObject","inLanguage":"es","@id":"https:\/\/cirasync.com\/wp-content\/uploads\/2026\/01\/Ema-Zulic.jpg6908e25f5b970f7afc565f7c922b5564","url":"https:\/\/cirasync.com\/wp-content\/uploads\/2026\/01\/Ema-Zulic.jpg","contentUrl":"https:\/\/cirasync.com\/wp-content\/uploads\/2026\/01\/Ema-Zulic.jpg","caption":"Ema Zulic"},"description":"Ema Zulic is the Vice President of Product Management and Customer Support at Cira Apps Ltd, where she drives product strategy, customer experience, and global support operations. With over 10 years of SaaS support expertise and more than 20 years of overall customer support leadership, Ema is blending deep technical insight with a passion for building high\u2011performing, customer\u2011centric teams. Her work focuses on delivering intuitive products, refining support processes, and creating seamless experiences for enterprise organizations. Outside of her leadership role, Ema shares practical, real\u2011world guidance to help companies strengthen their support models, improve operational efficiency, and elevate the customer journey.","url":"https:\/\/cirasync.com\/es\/author\/ema-zulic\/"}]}},"authors":[{"term_id":13546,"user_id":12,"is_guest":0,"slug":"ema-zulic","display_name":"Ema Zulic","avatar_url":{"url":"https:\/\/cirasync.com\/wp-content\/uploads\/2026\/01\/Ema-Zulic.jpg","url2x":"https:\/\/cirasync.com\/wp-content\/uploads\/2026\/01\/Ema-Zulic.jpg"},"avatar_alt":"","avatar_decorative":"","author_category":"1","first_name":"Ema","last_name":"Zulic","user_url":"","job_title":"","description":"<strong>Ema Zulic<\/strong> is the Vice President of Product Management and Customer Support at Cira Apps Ltd, where she drives product strategy, customer experience, and global support operations. With over <strong>10 years of SaaS support expertise and more than 20 years of overall customer support leadership<\/strong>, Ema is blending deep technical insight with a passion for building high\u2011performing, customer\u2011centric teams. Her work focuses on delivering intuitive products, refining support processes, and creating seamless experiences for enterprise organizations. Outside of her leadership role, Ema shares practical, real\u2011world guidance to help companies strengthen their support models, improve operational efficiency, and elevate the customer journey."}],"_links":{"self":[{"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/posts\/74443","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/comments?post=74443"}],"version-history":[{"count":4,"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/posts\/74443\/revisions"}],"predecessor-version":[{"id":74447,"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/posts\/74443\/revisions\/74447"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/media\/46654"}],"wp:attachment":[{"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/media?parent=74443"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/categories?post=74443"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/tags?post=74443"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/cirasync.com\/es\/wp-json\/wp\/v2\/ppma_author?post=74443"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}