How to switch payroll providers without breaking a pay run

Payroll is the only system in your stack where a botched migration is visible to every employee on the same morning. It is also, by some distance, the least forgiving category to evaluate: 1 of the 9 payroll tools we track offers a free tier, against 56% across software generally. You are going to commit before you can test.

So the work is front-loaded. Here is the sequence that keeps a pay run intact.

Switch at a quarter boundary, not a month boundary

Year-to-date figures have to move with you. Tax filings are quarterly, and a mid-quarter switch means one of two providers files a partial quarter — which is where the errors and the amended returns come from.

The cleanest windows are 1 January and the first day of any quarter. January is cleanest of all, because YTD starts at zero and nothing has to be migrated at all.

Run parallel for one cycle

Run the old and new systems side by side for a single pay period and reconcile before you switch off the old one. You are checking four things: gross pay, every deduction, employer taxes, and net pay per person.

This costs you one month of double subscription. It is the cheapest insurance in this entire process, and it is the step most often skipped for exactly that reason.

Get your data out before you cancel anything

Export and keep, at minimum: YTD earnings and deductions per employee, tax filings for the current year, employee records with start dates and classifications, benefit deductions and their rates, and any garnishment orders.

Access to a cancelled payroll account is not reliable, and the people who can retrieve it are the people you have just stopped paying.

Know what the price actually is at your headcount

Payroll is priced per employee almost universally — 9 of the 9 tools we track charge per seat. A base fee plus a per-employee rate behaves very differently from a flat plan as you grow, and the headline number tells you almost nothing.

Gusto, for example, charges a monthly base plus a per-employee amount. At one employee that is a small number. At fifty it is a different budget line entirely. Work it out at your real headcount, and again at the headcount you expect in eighteen months.

Tell employees before the first new payslip

The payslip will look different. Direct deposit may land at a different hour. The self-service portal will be somewhere else with a new password.

One short message before the first run prevents most of the support load, and its absence is the single most common reason a technically successful payroll migration feels like a failure.

Per-employee pricing and free-tier status verified from each vendor’s own page. Compare the options in our HR and payroll roundup.