October Payroll Checks: RTI, Starters and Leavers Before Year-End Pressure Builds

October is the quiet month for payroll, which is exactly why it is the right month for checks. By December the payroll team is firefighting: Christmas pay dates, bonus runs, and the January self-assessment overlap. The errors that surface then were all visible now. A focused October review takes a day and prevents the December scramble.

1. Reconcile RTI submissions against payroll records

Pull your Full Payment Submissions for the tax year to date and reconcile them against your payroll software: gross pay, tax, National Insurance, starters, leavers. Mismatches here are the single most common source of HMRC queries, and they compound silently. An October reconciliation catches six months of drift while there is still time to correct it cleanly.

2. Audit your starter and leaver records

Check every starter this year has a correct starter declaration and tax code, and every leaver has a P45 issued and the correct leaving date. Starter errors produce wrong tax codes that take months to unwind; leaver errors produce duplicate employments on HMRC's side. Both are five-minute fixes now and five-week sagas in January.

3. Review benefits and expenses reporting

If you payrolled benefits in kind, confirm the taxable values are flowing through correctly. If you did not, start planning the P11D data capture now rather than discovering in June that nobody kept the records. Benefits reporting is the area most likely to be wrong and least likely to be checked until it is too late.

4. Check pension contributions and auto-enrolment compliance

Reconcile pension deductions against contributions actually paid to the scheme, and confirm every eligible worker is enrolled with the right contribution rate. Auto-enrolment errors attract The Pensions Regulator, whose fines start small and escalate fast. October is also the moment to diary next year's re-enrolment date if it falls in 2027.

5. Validate employee data: names, addresses, NI numbers

A surprising share of payroll errors trace to bad master data: a misspelled name that mismatches HMRC's record, an old address, a missing National Insurance number for a starter. Run a data quality check now. Clean data is the cheapest payroll control there is.

6. Confirm your payroll calendar for December and January

Christmas and New Year move banking days, and RTI has strict timing rules around early and late payments. Agree the December pay date now, communicate it to staff, and confirm your payroll provider or software handles the RTI reporting for the shifted date. Deciding this in the second week of December is how mistakes happen.

7. Confirm software and rates are current

Finally, check your payroll software is updated for the 2026/27 tax year: current tax thresholds, National Insurance rates and thresholds, student loan thresholds, and statutory payment rates. Run a test RTI submission if your software allows it. Outdated rates are an embarrassing and entirely avoidable source of errors, and October is the calm moment to confirm everything is current.

The Bigger Picture: Payroll as a Control Environment

Payroll is not just paying people; it is one of the largest and most regulated cash outflows in the business. Treating it as a control environment, with reconciliations, checklists, and a calendar, is what separates employers who never think about payroll from employers who think about nothing else in December. The October check is the highest-value hour you will spend on payroll all year.

If payroll keeps competing with everything else for attention, that is a sign the function needs dedicated ownership. Finex Outsourcing (Global Business Services) provides outsourced payroll support for UK employers, from RTI compliance and auto-enrolment to year-end reporting, as part of our financial accounting outsourcing services, so the checks happen on schedule and December stays calm.