Merging tenants. Splitting tenants. ShareGate handles both in M365.

With ShareGate, merge the tenants in order, so each step has somewhere to land. First, size the source tenant before you commit to a date. Then migrate users, guests, groups and licenses. Then each user's mailbox and OneDrive. Then SharePoint sites and Teams. Every copy ends with a report, and re-runs pick up what changed until cutover. Once you're merged, ShareGate can also reorganize the combined tenant and keep it clean.

A divestiture is a merger in reverse. The business leaves with its users, mailboxes, files, sites and teams, and moves to the new owner's tenant. Migrate its users and groups first, then its mailboxes and OneDrives, then its sites and Teams. ShareGate only copies, so the original stays in place until you delete it.

With ShareGate, plan first, move in order and clean up after. Start by sizing the source tenant. Migrate users and groups, so mail, files, sites and Teams have somewhere to land. Copy mailboxes and OneDrives: destination mailboxes need licenses, and destination OneDrives need to exist. Move SharePoint sites and Teams. Then reorganize the combined tenant if it needs it, and keep it clean from day one.

Yes, all five. ShareGate's desktop app moves users, mailboxes, OneDrives, SharePoint sites and Teams from one tenant to another, and you get one vendor and one support team for all of it. You run each move separately, in order, and each one ends with its own report. Two things to know: users must be cloud accounts, not synced from an on-premises Active Directory, and mailboxes must be in Exchange Online. Planning happens in ShareGate's web app, and bulk OneDrive moves and Teams private chats use PowerShell.

Let them keep working in the old tenant until the last minute. ShareGate copies instead of moving, so nothing disappears from the old tenant while you migrate. Re-run your copies as often as you need, and each pass brings over only new mail, changed files and new conversations. If you move people in waves, mail sent to someone's old address is forwarded to their new mailbox. On cutover day, users reset their password once with a code sent to their old email, and their mail and files are already in the new tenant.

It depends on how much you have to move, so start by sizing your tenant with ShareGate's migration assessment before you commit to a date. Mailboxes usually set the timeline. Microsoft caps every tool at about 1.5 GB per mailbox per hour, so a 100 GB mailbox takes around 67 hours no matter what. ShareGate copies 16 mailboxes at once per machine, and adding machines lets you copy more at the same time. Start with the biggest mailboxes and the rest finishes around them.

You decide, with ShareGate's domain mapping. Pair each old domain with a new one, and ShareGate uses those pairs to match existing accounts and create new ones. The same pairs update dynamic group rules and distribution list aliases. Users match on their exact UPN, and you can type a new UPN to create a fresh account. Mapping works on whole domains, not single users. ShareGate doesn't switch your mail domain: you do that by changing DNS and MX records in Microsoft 365.

Partners deliver every ShareGate tenant-to-tenant project the same way. Your consultants learn one desktop app, and you deal with one vendor and one support team for content and users. Show up to the first meeting with the client's real numbers. Load their mapping file, and write what won't come across into the scope before it's signed. Hand over a report for every copy. The saved matches carry over to the next wave or acquisition, and an access check after cutover is your next piece of work.