Simple assessment is an alternative to self assessment where income tax cannot be collected through pay as you earn. The types of income that are commonly dealt with under simple assessment include the state pension and bank and building society interest (BBSI).

The simple assessment letter (PA302) includes a calculation of the tax due based on the information held by HMRC. The letter may be sent through the post or to the taxpayer’s personal tax account, if they have one.   

Increasing numbers of letters 

In July 2026, HMRC said that it was in the process of issuing the first batch of simple assessment letters for 2025/26, and that it expects to send approximately 1.8m letters in total. This is significantly higher than the 675,000 letters HMRC issued for 2021/22 – just five years ago – with the increase due in part to the freezing of the income tax personal allowance at £12,570.

*Rounded to nearest thousand. Figure for 2024/25 is HMRC’s latest estimate.  

It is likely that more taxpayers will receive simple assessment letters in the future as, under current plans, the personal allowance will remain at £12,570 until April 2031 at the earliest. This could include pensioners, particularly as the new state pension is expected to exceed the personal allowance for the first time from April 2027.  

However, at the Autumn Budget 2025, then Chancellor Rachel Reeves said the government would ensure “that people only in receipt of the basic or new State Pension do not have to pay small amounts of tax through Simple Assessment from April 2027”. It is not yet clear how this will be achieved.  

HMRC’s timetable 

In July 2026, HMRC said that it had begun to send letters for 2025/26 to working-age taxpayers, and that it would begin to write to pensioners from 12 August 2026. HMRC expects to send a second tranche of letters – relating to bank and building society interest (BBSI) data – between October and December 2026.  

It is possible that a taxpayer may receive more than one letter for a tax year. An earlier article explains how to proceed where this is the case. 

Action to take 

Taxpayers receiving a simple assessment letter are encouraged to check it thoroughly and to call or write to HMRC if they:  

• Have any queries. Before contacting HMRC, taxpayers may wish to read HMRC’s guidance:
  • for pensioners; 
  • on checking a simple assessment tax bill (which includes a link to a useful online tool); and
  • on calculating tax on BBSI.
• Believe that the letter contains an error. It is important that taxpayers check the figures used in the simple assessment calculation to their records, and contact HMRC to ensure that any figures that have been estimated based on historic amounts (eg, pension contributions) are replaced with accurate figures.
• Think it should be withdrawn. Where a simple assessment letter is sent to a taxpayer who is within self assessment, the taxpayer (or their agent) should contact HMRC and ask for the simple assessment to be withdrawn.

Paying the tax due 

The due date for paying a simple assessment tax bill for 2025/26 is 31 January 2027, unless a different date is shown on the letter. HMRC has published guidance on how to pay a simple assessment tax bill.  

If the taxpayer believes they will be unable to pay their tax bill in full by the due date, they may wish to consider contacting HMRC to agree a time to pay arrangement.