Consolidating payroll across six entities and fourteen states

A group of six legal entities formed through four acquisitions, with more than 500 employees across fourteen states. We consolidated four separate payroll systems into one platform, completed the transition at the start of Q4 2025, and have managed their payroll operations since.

Each acquisition brought its own payroll system, and each one continued operating independently. No one had taken ownership of bringing them together. The deal team's role ended at closing, and no integration process had been put in place afterward.

Nobody could say which entity employed which people. That was not just a reporting issue, it affected state registrations, wage base tracking for transferred employees, and the EIN that appeared on each W-2. Without a clear employee-to-entity structure, every downstream payroll process was at risk.

The same person could exist twice. Two systems, two spellings, two records, one human being.

State registrations were wrong in some states and missing in others. Fourteen states is not one job repeated fourteen times. Every state means a withholding account, an unemployment account with its own rate, its own deposit schedule and filing calendar, and in some states local taxes underneath. Across six entities that is up to eighty-four separate relationships to get right.

We answered the employer question first, from documents rather than from the payroll system. That required reviewing offer letters and, in some cases, acquisition documents. For 8% of employees, the payroll system did not match the paperwork. The documentation was treated as the source of truth. These issues were identified during preparation, before the transition, when corrections were still simple and low-cost.

We matched duplicate records and confirmed every one. Slow, and deliberately so. Merging two records that turn out to be two different people is a much worse outcome than leaving them apart, so nothing was merged on a name match alone.

We checked every state registration against where people actually work, and fixed what was missing or wrong.

We went live at a quarter boundary. The best day to switch payroll is 1 January, because there is no history to carry across. The next best is the first day of a quarter. Switch in the middle of one and the Form 941 covers three months that two providers each half-hold, and neither can file it cleanly. Across six entities and fourteen states that is not one awkward filing, it is potentially dozens.