A tenant-to-tenant migration
Two Microsoft 365 environments become one, typically after an acquisition or restructuring, with mailboxes, files, and identities moved deliberately.
A new office or site
A new location needs its own network handoff, device baseline, and access setup before it's treated as part of the regular tenant.
A legacy system moves in
An on-premises application or file share is retired in favour of a Microsoft 365-native replacement, changing what the recurring plan now covers.