800+ SharePoint sites migrated and governed

Our summary

We delivered the migration, information governance and Copilot readiness as a single programme over seven months.

The situation

A national regulator was running SharePoint 2013 on-premises across more than 800 sites. The platform was out of support, the information architecture had grown organically for a decade, and almost nothing was classified.

Copilot was on the roadmap. That made the classification gap urgent: an AI assistant with access to hundreds of unlabelled sites is an information-governance incident waiting to be written up.

The migration

We led the technical move into a modern SharePoint Online information architecture using ShareGate, directing pilots, delta cutovers, wave-based validation and the formal decommissioning of the legacy environment.

We rebuilt access management around an Entra ID dynamic-group governance model, automating joiners, movers and leavers against directory attributes so permissions track organisational status rather than institutional memory.

Copilot readiness

We designed a Microsoft Purview service-side auto-labelling strategy across Public, Internal Use Only, Confidential and Strictly Confidential, with supporting DLP and retention policies that preserved the historical metadata required for audit.

We configured Copilot governance to block AI access to unlabelled content, so Copilot only works with classified data. We evidenced access-control reviews across the estate through the Microsoft 365 Unified Audit Log, and the branded, responsive intranet went live integrated with Teams and Viva.

The result

More than 800 sites moved from SharePoint 2013 to SharePoint Online, and the legacy environment was formally decommissioned.

The regulator now has a four-tier labelling scheme with DLP and retention, Copilot governance built on those labels, and a live intranet in Teams and Viva.