Where payroll errors start
The errors that do the most damage tend to fall into four areas: how pay is calculated, which deductions come out of wages, when payments and submissions reach HMRC, and whether the tax data behind each run is current. A mistake in any one of them often repeats on every pay run until someone spots it, which is why the sections below take each area in turn and set out what to check.
The four errors that cause most of the damage
Four error types account for most of the damage: miscalculated pay, incorrect deductions, late PAYE payments and out-of-date tax data. Each section below explains how the error happens and what to check to stop it.
1. Miscalculated pay
Wage calculation is where many errors start. Overtime and commission rules applied inconsistently, hours that do not match the timesheet or rota, and holiday pay worked out on the wrong basis are the usual culprits. Where an error has already reached an employee's bank account, agree the correction with them in writing, then make sure the corrected figures flow through to your next submission to HMRC.
2. Unlawful or incorrect deductions
Deductions are tightly restricted. Under section 13 of the Employment Rights Act 1996, a deduction from wages needs a statutory basis, a contractual basis, or the worker's prior written consent. Paying less than is properly due also counts as a deduction, so clawing back an overpayment from a later pay packet without agreement can create a fresh problem.
Recovering an overpayment is possible, but the cleanest route is a repayment method agreed in writing. For large amounts, a repayment plan the employee can actually afford is fairer and easier to defend.
3. Late PAYE payments to HMRC
Late payment is where penalties most often arise. Penalty exposure only starts with the second late payment in a tax year, because the first one is disregarded for default counting, as LITRG explains. From there the rate rises with the number of defaults, and HMRC's own guidance sets out the full bands for monthly and quarterly payers.
The bill can grow after the penalty too. Further surcharges apply if the debt is still unpaid at six and twelve months, as Croneri's PAYE guide sets out. Meanwhile, Sterling & Wells points out that daily interest starts the day after a missed deadline, so a short delay can cost more than the original shortfall.
4. Outdated tax data and missed rate changes
Most errors that repeat over time trace back to three things: rates that changed but were never loaded, tax codes not updated after an employee's circumstances changed, and reporting that went out late. A tax code can shift when someone takes a second job, receives a benefit, or when HMRC issues an update. If payroll does not reflect that, tax is either overpaid or underpaid on the employee's behalf.
The fix is a regulatory calendar that tracks rate changes, with tax codes checked against HMRC notices every month rather than once a year.
What the penalties look like
Penalties depend on the type of error. Late submissions and payments attract charges set by employer size or by default history, while National Minimum Wage underpayments carry the steepest exposure. Let’s explore these in more detail.
Late Full Payment Submissions
Payroll information has to reach HMRC on or before the day employees are paid. LITRG notes that HMRC compares submission dates with payment dates, so a late submission can generate a notice even when the tax itself arrived on time. Late filing penalties are set by employer size and charged on a monthly basis.
National Minimum Wage and the Fair Work Agency
Underpaying the National Minimum Wage carries the steepest exposure. Grant Thornton puts the penalty at 200% of the total underpayment, capped at £20,000 per worker. Ostberg Sinclair points to a change of enforcer: the Fair Work Agency now handles NMW compliance in place of HMRC, and a named employer can appear once arrears pass a low threshold.
Reputational damage
Underpaying employers can end up on the government's naming list. The latest round, reported by VWV, suggests enforcement is tightening, with the Fair Work Agency expected to hold full powers from April 2027. Being named puts an employer in front of staff, candidates and clients, a cost no penalty figure captures.
What an error costs beyond the penalty
The penalty is only part of the bill. A pay error can erode trust and prompt resignations, and it consumes management time while it is investigated and corrected. Replacing someone who leaves over a pay problem adds recruitment and onboarding costs. Teams that keep a clear error log and a fast correction process keep these costs down.
The cost of an error also reaches the people it lands on. In the UK Payslip Anxiety Report from Access PeopleHR, 63.85% of workers said they had received incorrect pay at some point in their employment. Over 21% of respondents also reported having to borrow money because of errors or delays. That personal impact is what payroll teams are working against when a run goes wrong.
How to prevent payroll errors
- Audit at least once a year. Review pay rates, tax codes, pension contributions, starters and leavers, and holiday accruals. A quarterly check of tax codes and starters is better still.
- Reduce manual input. Every manual re-keying step is an opportunity for error. Where possible, integrate payroll with time and attendance so hours flow through without retyping.
- Run pre-payroll checks. Before each run, compare gross-to-net totals, new starters, leavers and changes against the previous period. Investigate every variance before you release the run, not after.
- Keep your knowledge current. Rate changes, tax code updates and enforcement priorities all move during the year. Assign one person to own the regulatory calendar, and budget for training.
Next steps
Payroll errors are rarely one-off events. They tend to repeat until the process changes. Start with an audit, remove the manual steps that create the most risk, and build a calendar that keeps your rates and codes current.
If you want to see how your current process compares, watch a four-minute demo or contact the PeopleHR team.
