Disputing a PAYE coding notice

A PAYE coding notice should be checked against current income, benefits and allowances rather than treated as a final annual tax assessment. Use HMRC’s official process to update inaccurate information and keep evidence of the figures supplied.

Compare notices across employments or pensions and identify estimated amounts. Payroll normally follows HMRC coding instructions; the underlying information may need correction with HMRC.

Identify the code and the income source it belongs to

Collect the coding notice and a recent payslip or pension statement. Record the tax year, employer or pension payer, code and date it began to be used. HMRC provides a code for each employment or pension, so a person with several sources should not assume that one code is intended to apply everywhere. ^[1] Check that the notice being reviewed belongs to the correct payer and period.

Prepare a list of current and ended employments and pensions, with start and leaving dates. Include the estimated annual taxable income shown in HMRC's records where available. A coding problem can arise from missing or outdated information, such as an employment that still appears active. The first task is to identify the incorrect input rather than asking an employer to select a preferred code without HMRC's instruction.

Compare the notice with the underlying facts

Read the explanation of allowances and adjustments on the notice. Compare employment benefits, estimated income and other relevant entries with the documents available. If a company benefit has ended, record when and obtain the employer's supporting information. If an income estimate is unrealistic, prepare a supportable replacement based on actual pay and expected remaining earnings rather than simply reducing it until the deduction looks comfortable.

Keep separate any amount relating to an earlier tax year or another source of income. A coding adjustment may be collecting something beyond tax on the current month's pay, so the net payslip alone may not explain it. Ask for the item to be identified and reconciled. Do not assume a lower net payment necessarily proves that the code itself is invalid.

Update HMRC through the appropriate service

HMRC directs taxpayers who think a code is wrong to check and update the employment, pension, estimated income, benefit and expense information it holds. Its online Income Tax service is one route, with contact options where the service cannot be used. ^[2] Use official access and retain a record of the information changed. An agent should use the appropriate authorised process rather than the taxpayer's personal credentials.

If you have recently started a job, check the current HMRC guidance about allowing new employment information to arrive and ensure the employer has the appropriate starter information. Obtain a missing P45 from the previous employer where relevant. Keep the request focused: identify the inaccurate entry, the correct fact and supporting dates. This is easier to act on than a general statement that too much tax has been deducted.

Follow the correction into payroll

When HMRC changes a code, check the new notice and later payslips to see that the employer or pension provider has received and applied it. HMRC's guidance explains the expected sequence and what to do if the new code does not appear. ^[2] Avoid assuming that updating an online income estimate changes the next payslip immediately, particularly where payroll processing has already taken place.

Record the date of the request, the revised code and the first payment using it. If the payslip still differs from the notice, ask payroll which instruction it holds and when it was received. Preserve both documents. A useful follow-up identifies the mismatch between a particular notice and a particular payroll period rather than reopening the entire annual tax position without a clear question.

Reconcile the annual outcome separately

A corrected code changes tax collection, but the final annual position still depends on actual income, reliefs and tax deducted. Keep P60s, benefit records and any year-end calculation for review. Where Self Assessment is required, make sure the return reflects the source documents and tax already collected. Reviewing a Self Assessment calculation explains the distinction between an annual calculation and an account statement when checking the final balance.

For assistance reviewing a coding discrepancy and its supporting information, see Tax penalty appeal preparation. Provide the current notice, relevant payslips and a short employment or pension timeline. Explain the specific item you believe is wrong, such as an ended benefit or duplicate employment. That allows the review to focus on the cause and the appropriate correction process rather than promising a particular refund before the full position is understood.

Retain a concise outcome note showing what HMRC changed and any issue left unresolved. If the estimate will change again because of a bonus, retirement or reduced hours, note when it should be reviewed. Keeping these future changes visible helps prevent an otherwise correct code becoming unsuitable later in the same tax year.

Illustrative scenario

A pensioner’s code includes an outdated estimate of savings interest. They provide the current information through the official service and retain confirmation for the next payslip review.

Preparation checklist

• Check the coding components
• Identify outdated estimates
• Compare income sources
• Retain update confirmation