Some taxpayers have already started to receive Simple Assessment letters from HMRC for the 2025-26 tax year, with a further tranche due to be sent between October and December 2026.

Simple Assessment is used where HMRC cannot collect income tax through PAYE or self-assessment. The PA302 letter sets out HMRC’s calculation of the tax due, based on information it holds. Common examples include tax due on pension income, savings interest, dividends or if the taxpayer has a second source of income that has not been taxed. It can also apply where someone has received more tax-free allowance than they were entitled to, or where the amount owed cannot be collected through a tax code, typically £3,000 or more.

HMRC began sending letters to working-age taxpayers from 30 June 2026, followed by letters to pensioners from 12 August. A second tranche, relating to bank and building society interest (BBSI) data, is expected to be issued between October and December 2026. In some limited cases, taxpayers may receive more than one letter for 2025-26.

Tax can be paid in full or by instalments, with the deadline depending on when the Simple Assessment letter is received. For the 2025-26 tax year, letters received before 31 October 2026 require payment by 31 January 2027. Letters received on or after 31 October 2026 require payment within three months of the date of the letter. 

HMRC expects to issue around 1.8 million Simple Assessment letters for the year. Taxpayers receiving a letter should check the calculation carefully against their own records and contact HMRC if they believe any information is incorrect or the assessment should be withdrawn. 

If you receive a Simple Assessment letter and are unsure whether the calculation is correct, what you need to pay or what action you should take, please contact us. We can review the assessment and help you understand what it means and how to deal with it.