HM Revenue and Customs has apologised after a calculation error in its self-assessment system overcharged income tax on the state pension for around 1.7 million pensioners. The mistake is small for most people, about 5 pounds each, but there is no automatic refund: the onus is on affected pensioners to spot it and reclaim.
| Quick answerHMRC pre-filled state pension income in the self-assessment return at 52 weeks of the new, higher rate, when its own rules require one week at the old rate and 51 weeks at the new rate. This overstated taxable pension income by about 9.05 pounds for the 2025-26 tax year and added roughly 5 pounds to many tax bills. Around 1.7 million self-assessment filers were affected, totalling about 43.5m pounds. There is no automatic refund: affected pensioners must check their figure and contact HMRC to correct it. |
What went wrong
The state pension is taxable income, but tax is not deducted before it is paid. For people who complete a self-assessment return, the HMRC online tool pre-filled the state pension figure using a flat 52 weeks at the new, higher rate that applies after the April uprating. HMRC guidance says the entry should reflect one week at the old rate and 51 weeks at the new rate, because entitlement builds up across the tax year. The Department for Work and Pensions supplies pension data on a flat 52-week basis, while HMRC reporting rules use a split-week method. The error was identified by the accountancy firm Grant Thornton.
| Item | Figure |
|---|---|
| Self-assessment filers affected | Around 1.7 million |
| Estimated total overcharged | Around 43.5m pounds |
| Typical individual overcharge | About 5 pounds |
| Overstated taxable income | About 9.05 pounds |
What to do
- If you have not yet filed your 2025-26 return, check the pre-filled state pension figure against your DWP uprating letter and correct it before submitting.
- If you have already filed and paid, contact HMRC to correct the figure and reclaim any overpaid tax. There is no automatic refund.
- Keep your own record: the state pension has no P60, so the taxable figure must be tracked by the individual.
| HMRC has said it expects to resolve the issue later this summer. Even after a fix, the responsibility to check and reclaim past overpayments stays with the taxpayer. |
This article is for general information only and reflects publicly reported figures as at June 2026. It is not tax advice. Confirm your own figures with HMRC or a qualified tax adviser, and free help is available from the Low Incomes Tax Reform Group or Citizens Advice.
Frequently asked questions
How much was I overcharged?
For most affected pensioners the difference is about 5 pounds, from roughly 9.05 pounds of overstated taxable income for the 2025-26 tax year.
Will I get an automatic refund?
No. You need to check your figure and contact HMRC to correct it and reclaim any overpaid tax.
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