When two companies combine, the IT teams inherit the hard part. Identity systems,...

When two companies combine, the IT teams inherit the hard part. Identity systems, mailboxes, and shared resources rarely line up cleanly, and that friction shows up in every calendar invite and access request until someone sorts it out. The market numbers back this up. Post-merger integration consulting is projected to grow from 1.34 billion to 4.17 billion by 2035. That growth tracks with what we see on the ground, where the volume of AD and Microsoft 365 consolidation work keeps climbing after deals close. The organizations that move fastest are the ones that treat identity matching and coexistence as the first real deliverable, not an afterthought. Everything else, from file access to compliance checks, depends on getting that foundation right. In our last large logistics integration we watched the same pattern play out at 16,000 users. The teams that planned the directory work early spent far less time chasing permissions afterward.