Written By Gerson Pacheco Â
If your organization is planning a Commercial to GCC High migration, the transition requires more than simply moving data. Whether you’re preparing for CMMC, aligning with federal compliance requirements, or supporting a public-sector mission, you need clear goals and proper planning to make the migration successful.
This guide breaks down the essential areas to evaluate before moving your Microsoft 365 Commercial tenant into GCC or GCC High—from user counts and mailboxes to SharePoint sites, Teams, and overall data hygiene.
1. Understand Your Environment: Start With Discovery
Before beginning any Commercial to GCC High migration, take a complete inventory of your current Microsoft 365 environment. Identify:
- Total number of users
- Types of data you’re storing
- Which services (Exchange, SharePoint, Teams, OneDrive) are actively in use
This discovery phase influences every decision you make. Your CSP’s assessment tools can help map user activity, mailbox sizes, and app usage, giving you an accurate picture of what truly needs to move.
2. User Counts: Who Actually Needs to Migrate?
Not every account in your Commercial tenant will require a license in GCC or GCC High. Review:
- Active users vs. disabled or stale accounts
- Guest accounts (and whether they must be recreated)
- Service accounts tied to automated processes
Once you determine who is active and essential, you can accurately estimate GCC or GCC High licensing needs—important because these environments often cost more due to their compliance and security controls.
3. Mailboxes: Decide What Should Make the Move
A Commercial to GCC High migration is the ideal moment to clean up your mail environment. Consider:
- User mailboxes: Prioritize active users. Archive or exclude inactive mailboxes.
- Shared mailboxes: Determine whether teams still use them. Retire unused ones.
- Resource mailboxes: If rooms or equipment aren’t being booked, you can skip them.
- System mailboxes: These typically stay behind unless still needed.
Think of this as decluttering before you move into a secure, compliance-focused environment.
4. SharePoint Sites: Clean Up Before Migration
SharePoint sprawl accumulates quickly, and you don’t want to bring digital clutter into GCC or GCC High. Before migrating:
- Review activity logs
- Identify site owners
- Archive or delete inactive sites
- Consolidate redundant sites
A cleaner SharePoint landscape results in a faster, smoother migration—and lower costs.
5. Evaluate Teams, OneDrive, and Third-Party Integrations
Mail and SharePoint get most of the attention, but a Commercial to GCC High migration affects much more:
- Teams: Determine whether channel history, files, and apps need to be recreated.
- OneDrive: Decide which files require migration and which users can manually move.
- Third-party apps: Many integrations aren’t supported in GCC High and may need replacement.
Prepare users for what may change or disappear in the government cloud.
6. Plan for Downtime and Clear Communication
Because Commercial and GCC/GCC High are isolated cloud environments, there is no direct full-fidelity tenant-to-tenant migration path. Expect:
- Possible downtime
- App reconfiguration
- New login processes
- Temporary coexistence issues
Success depends on communicating timelines, expectations, and post-migration training.
Final Thoughts
A Commercial to GCC High migration isn’t just technical—it’s a strategic move toward stronger security and compliance. The best outcomes come from planning ahead, cleaning up unused data, understanding what must move, and preparing users for changes in the government cloud.
Working with an experienced CSP can make the entire process smoother, faster, and more predictable—helping you land in a secure, compliant tenant built for your organization’s mission.