Changing payroll providers: protect the first live payday
Switching payroll providers is usually manageable, including during a tax year, but it is a data-reconciliation and ownership project—not simply a login change. Incorrect year-to-date figures, duplicated employee identifiers or misunderstood pension responsibilities can contaminate subsequent runs.
Choose a first live payday, work backwards from it and make a named person accountable for sign-off at each stage. If the timetable does not allow a proper reconciliation, delaying the switch can be cheaper than fixing a live payroll.
The migration data pack
Your outgoing provider or internal team may need to supply the following through a secure agreed channel—not an initial sales email.
| Area | Required information | Why it matters |
|---|---|---|
| PAYE scheme | Employer PAYE and Accounts Office references, reporting configuration | Correct RTI association |
| Employees | Names, addresses, payroll identifiers, NI details where held, starter/leaver dates | Matching records without duplicates |
| Year to date | Taxable pay, PAYE, NIC categories, student loans and statutory pay where relevant | Accurate future calculations and reconciliation |
| Pay setup | Salary/rates, frequency, recurring additions and deductions | Correct first run |
| Pensions | Scheme, enrolment status, contribution basis and historical records | Ongoing employer duties and continuity |
| Historical outputs | Prior payslips, reports, journals, prior submissions and corrections | Exception checking and audit trail |
| Authorities | Submission credentials, bank permissions and approval contacts | Avoiding unauthorised or duplicate actions |
The data needs minimum necessary access, a secure transfer and a reconciliation plan. For the legal reporting fields, check HMRC's current FPS/EPS guidance.
A six-step switching playbook
1. Name your deadlines
Record the final old-provider run, first new-provider run, cut-off dates, test-run date, employer approval and earliest release/payment deadline. Include a public-holiday buffer.
2. Request data early and document the gaps
Agree the format—ideally usable structured exports rather than hundreds of PDFs. Create a log of missing employee records, outstanding deductions and unresolved prior-year corrections. Check the outgoing contract for exit fees and data-return duties.
3. Reconcile before you import
Compare headcount, PAYE totals and year-to-date values against authoritative source reports. Pay particular attention to payroll IDs for people with multiple employments, rehires, starters and leavers. An apparent difference of £5 may indicate an underlying configuration error.
4. Run a controlled test
For a representative pay cycle, calculate gross/net totals and compare to an expected baseline. Test at least one starter, leaver, variable-payment change, pension case and loan deduction if applicable. In a parallel run, agree which provider is permitted to submit real RTI so duplicate submissions cannot occur.
5. Approve and go live
The employer approves the final payroll and any payment release under the agreed authority process. Record when the appropriate HMRC returns are submitted and who will investigate rejections or errors.
6. Verify the first two paydays
Check employee queries, pension reconciliations, journals, PAYE liabilities and any unexplained variance. Retain an issue log with owner and resolution date. The first successful pay run is a milestone, not the end of migration.
Specific warnings to resolve before switch-over
- The old provider will supply only PDF payslips, with no machine-readable YTD export.
- Nobody can explain why the employee headcount differs between pension and payroll reports.
- The new team has not defined who can authorise bank account changes or make payments.
- Two organisations may both make RTI submissions for the same pay cycle.
- You cannot obtain a written data-processing agreement or confidentiality obligations.
See the payroll security guide and the provider comparison framework. To explore a transition, send a high-level switching brief—without personal payroll data.