The Challenge
To keep working within the US defence supply chain, the organisation needed to move its Microsoft 365 estate out of a UK Commercial tenant and into a US GCC High environment that met its US defence regulatory and contractual requirements.
GCC High is a separate sovereign cloud, not just another tenant. Capabilities differ, cross-cloud boundaries limit what tools and integrations can do, and identity, administration and security controls all work differently on the other side.
The Approach
- Planned the migration in waves, with coexistence between the source and target environments so the business could keep working throughout.
- Moved Exchange Online, SharePoint Online, OneDrive for Business and Teams using MigrationWiz and ShareGate, with validation for each workload before cutover.
- Established a new Azure-hosted directory services foundation for the target environment using Microsoft Entra Domain Services.
The Outcome
The core collaboration estate was delivered into the GCC High target environment with workload-specific validation.
The organisation gained a target environment that supports its US defence regulatory and contractual requirements, with a clear operating model across identity, workloads and administration.
How We Worked Together
A move like this carries real business risk, so communication ran throughout the engagement rather than only at milestones. The customer always knew where the migration stood, what was coming next and what it meant for them.
Potential risks were raised early, before they became problems, so decisions could be made calmly and on the customer's terms rather than under pressure.
Issues that appeared during the engagement were worked through methodically. When the customer was worried something had gone wrong, the first step was always to stay calm, establish the facts and explain clearly what was happening and what would be done about it.
Every recommendation was made with the customer's best interests in mind: detailed, considered and focused on what would work for their organisation, not just on finishing the migration.