Post-merger integration (IT)
Post-merger integration (PMI) is the work of combining two organizations' IT after a merger or acquisition — identities, Microsoft 365 tenants, security baselines, tooling, and teams — into one environment.
When one company acquires another, the deal closes long before the technology is actually merged. PMI is the months of project work that follow: consolidating domains and Microsoft 365 tenants, unifying identity and access, aligning security baselines, migrating files and mailboxes, and rationalizing overlapping tools.
Why it's hard
PMI is high-stakes and deadline-driven — leadership wants 'one company' fast — and it's a dependency minefield. You can't migrate mailboxes before identity is sorted; you can't decommission the old tenant before data is moved and verified. A missed sequence means downtime for newly-acquired staff on day one.
Why playbooks win
MSPs that do M&A work repeatedly turn PMI into a repeatable playbook: a templated project with the right phases, dependencies, and checklists, adjusted per deal. That's faster and far less error-prone than planning each integration from scratch. Current ships PMI playbooks and dependency-aware scheduling so the tenant-merge sequence is planned, visible, and safe to execute.