HMRC begins sending Simple Assessment letters

HMRC started sending Simple Assessment letters from October 2025, giving a detailed calculation of tax owed on income received in the 2024/25 tax year, which ran from 6 April 2024 to 5 April 2025¹.

Simple Assessment is the route HMRC uses to collect tax from people who do not complete a Self Assessment tax return and whose tax cannot be collected through Pay As You Earn (PAYE)¹. TaxAid, an independent tax charity, says the process has been set up for people with straightforward tax affairs¹.

A letter may arrive where someone needs to pay Income Tax that is not automatically taken out of their income, for example if they have been on the wrong tax code, owe tax on bank or building society interest, or owe tax on their State Pension. It may also be sent where the person owes HMRC £3,000 or more¹.

The letter is form PA302 and states how much tax is owed, when it must be paid and how to pay it, including what to do if the recipient disagrees with the assessment. It will usually include why HMRC believes too little tax has been paid¹.

Payment deadlines

The deadline depends on when the letter was sent, according to TaxAid¹:

Payment can be made online or through the HMRC app, by bank transfer or by cheque¹.

Someone who thinks the assessment is wrong has 60 days from the date on the letter to query it with HMRC, by calling 0300 200 3300 or writing to PAYE and Self Assessment, HMRC, BX9 1AS. HMRC reviews the assessment and writes back to say whether it will be changed, withdrawn or kept the same¹.

Anyone already registered for Self Assessment who receives a Simple Assessment letter needs to call HMRC on 0300 200 3300 to have the Simple Assessment withdrawn¹.

Where tax is owed on bank or building society interest, two Simple Assessment letters may arrive in the same tax year. The second letter shows the total tax owed for the year, including the amount in the first letter even if that has already been paid. In that case the amount still owed is the figure in the second letter minus what has already been paid. HMRC should also be told about other income for the year not shown on the calculation, such as dividends¹.

Why it matters for households

The letters affect people outside Self Assessment whose tax cannot be collected through their PAYE code, including those with untaxed bank or building society interest, an incorrect tax code, or State Pension income that has not been taxed at source¹. The amount stated is a bill, not a refund, and the payment date is fixed by the date printed on the letter rather than by a single national deadline¹.

For letters sent before 31 October 2025, payment falls due on 31 January 2026. For letters sent on or after that date, the household has three months from the letter date¹. Because the second letter for interest tax restates the full year's liability, someone who has already paid the first amount needs to check the arithmetic to avoid paying twice¹.

The 60 day window to dispute a calculation runs from the letter date, so the time available to check the figures is set by when the post arrives¹.

What happens next

HMRC continues to issue the letters, and each carries its own payment date and its own 60 day query period¹. TaxAid's guidance was last updated on 20 January 2026¹.