Client wants to delay M365 cutover by 6 months after migration is complete, how do you handle the re-scoping conversation?
We just wrapped a Google Workspace to Microsoft 365 migration for a 350-user company — mail, shared drives, Google Drive, documents, the whole stack. Finished two weeks ahead of the original deadline and were fully ready for MX record cutover.
To give you a sense of the scale involved:
- 350 user mailboxes
- 50+ shared mailboxes with over 1 TB of mail data
- 50+ shared drives with over 200 GB of data
- Hundreds of shared drives with multiple terabytes of files
This wasn't a simple lift-and-shift. Getting all of that migrated, mapped, and verified was a serious effort. We're done. Everything is staged and ready.
At the last minute, the client requested a 6-month delay before cutover. Now we're stuck in a gray zone where we have to maintain both environments in sync for half a year:
- Ongoing delta mail syncs across 350 user mailboxes and 50+ shared mailboxes
- File delta across hundreds of shared drives — new files, renamed files, modified content, deletions
- New hires provisioned, departed employees offboarded on both sides
- Calendars, meeting invites, and email signatures kept current
- Any org-level policy or config changes mirrored across both platforms
This is a sustained managed migration service that was never scoped. Keeping a migration of this size in sync for 6 months is not a trivial background task — it's ongoing engineering work. The client is pushing back on any additional cost, arguing the migration "should already be done."
Our position: we were ready. The delay is entirely on their end. We're drafting a new Statement of Work to cover the extended sync period.
Questions for the community:
- Have you dealt with a client-initiated delay post-completion on a migration this size? How did you frame the commercial conversation?
- What's the cleanest way to structure a delta-sync SOW — fixed fee, T&M, or retainer?
- Did you get the delay in writing, and did that help when re-negotiating scope?
Appreciate any experience here.
P.S: We are fairly small MSP, and have only done dozens such migrations previously.