Committee publication · Correspondence · 6 July 2026

Letter from the Chief Executive and First Permanent Secretary at HMRC relating to State Pension taxation, 1 July 2026

From: Public Accounts Committee

Summary

John-Paul Marks, Chief Executive of HMRC, writes to inform the Public Accounts Committee of a historical error in State Pension taxation dating to 2010. HMRC used incorrect pension figures in PAYE reconciliations and Self Assessment calculations, affecting approximately 1.4 million PAYE pensioners in 2024/25 and up to 1.7 million others in Self Assessment and Simple Assessment. Most overpayments fell within HMRC's administrative tolerances (averaging £1.76–£2.30 per year for basic rate taxpayers), so actual tax collected often remained correct. HMRC commits to delivering a summer 2026 fix and has commissioned an internal audit.

Key findings

  • HMRC used incorrect State Pension figures (52 weeks at current-year rate instead of one week at previous rate plus 51 weeks at current rate) in PAYE systems since 2010/11, Self Assessment pre-population since 2015/16, and Simple Assessment since 2016/17, stemming from a 2010 systems change.
  • In 2024/25, approximately 1.4 million PAYE pensioners overpaid tax; up to 955,000 Self Assessment and around 760,000 Simple Assessment pensioners may have overpaid, with average losses of £1.76 (basic State Pension) to £2.30 (new State Pension) per tax year for basic rate taxpayers.
  • For the majority of affected pensioners, discrepancies do not result in actual tax refunds because overpayments fall within HMRC's longstanding administrative tolerances (small overpayments not automatically repaid; small underpayments not pursued).
  • HMRC will deliver a correction solution in summer 2026 to prevent future errors and correct 2025/26 calculations; will also enable Self Assessment returns filed for 2025/26 to be corrected.
  • Internal Audit has been commissioned to establish the full history and causes of the issue and ensure lessons are learned; Low Incomes Tax Reform Group (LITRG) has been engaged to support development of the solution and provide challenge on customer support.

Tone

Procedural

Topics

public-financetax-administrationpensionssocial-security

Key actors

John-Paul Marks, Sir Geoffrey Clifton-Brown, HM Revenue & Customs (HMRC), Department for Work and Pensions (DWP), Low Incomes Tax Reform Group (LITRG), Chartered Institute of Taxation, Comptroller and Auditor General

Notable line

I apologise for this error and especially to those pensioners who have been affected. I know that any shortfall matters, particularly to customers on fixed or limited incomes.

Key Quotes

An incorrect State Pension figure has been used in PAYE end-of-year reconciliations and has fed through into Self Assessment pre-population information and Simple Assessment calculations.
John-Paul Marks · Explaining the scope and mechanism of the error
… for the majority of pensioners these differences do not result in a change to the tax collected or repaid because they fall within HMRC's longstanding administrative tolerances
John-Paul Marks · Noting that most affected pensioners did not pay incorrect amounts overall
2024/25 tax year, around 1.4 million pensioners in PAYE paid too much tax because of this issue.
John-Paul Marks · Quantifying impact in the most recent tax year
I can confirm that we will deliver a solution this summer to correct future tax calculations.
John-Paul Marks · Committing to a timeline for fixing the issue
The complexity of the interaction between DWP State Pension data, PAYE end- of-year reconciliation, Simple Assessment and Self Assessment pre-population means developing a solution has taken until now and I apologise that …
John-Paul Marks · Explaining why resolution has been delayed
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Source · parliament.uk record ↗