Understanding simple assessments

Written by AJN Accountants
4 December 2025

If you owe income tax that cannot be collected automatically via PAYE, such as tax on bank interest or the state pension, HMRC may send you a simple assessment notice.

This letter shows how much tax HMRC believe you owe based on information they hold. It is important to check the figures against your own records, including bank statements and letters from the Department for Work and Pensions.

If you normally complete a self assessment tax return you should not also receive a simple assessment. If you do, HMRC must withdraw it. You have 60 days from the date on the notice to challenge the figures or request withdrawal. We can help you with this.

Most people will receive only one notice, but it is possible to get more than one for the same tax year. For example a taxpayer who has already received a letter for 2024-25 that did not include their bank and building society interest may receive a second letter taking that information into account. The updated notice will show the total tax due for the year, even if some has already been paid. Make sure you deduct any tax paid following the first letter from the tax shown as due in the second letter before paying the remaining balance.

The payment deadline depends on when the notice is issued. If it is dated before 31 October, the tax must be paid by 31 January the following year. For notices dated on or after 31 October, you have three months from the date of issue to pay the tax. If you cannot pay in full, HMRC’s new self-serve Time to Pay system allows you to set up an instalment plan online.

Simple assessment letters are now being issued for income earned in the 2024-25 tax year. Contact us if you have received a letter and you are not sure whether the calculation is correct.

Loans to directors: tax rate increased

An outstanding loan to a director or shareholder from a close company can trigger a tax charge under Section 455 of the Corporation Tax Act 2010. The director's loan account is generally used to account for temporary withdrawals from the business for the director's...

Self assessment payments via PAYE

From April 2029, income tax self assessment taxpayers who also have PAYE income will pay some of their self assessment liability via PAYE. Currently, if you owe additional tax due to a previous underpayment HMRC can collect that amount gradually by adjusting your tax...

New penalties regime for all income taxpayers

The new points-based penalties system will apply to all self assessment taxpayers from April 2027, not just those within Making Tax Digital for income tax (MTD IT). The new rules will apply first to taxpayers mandated to join MTD IT from April 2026 (those with...

Related Posts

Public EV charging standard-rated 

Public EV charging standard-rated 

HMRC has reconfirmed that supplies of electricity for charging electric vehicles (EVs) at public EV charging points is standard-rated for VAT purposes. Electricity supplied at public EV charging points is subject to VAT at the standard rate of 20%, rather than the...

Are you missing out on a PAYE refund?

Are you missing out on a PAYE refund?

Employees and pensioners are being encouraged to check whether they are due a PAYE tax refund. HMRC figures suggest that more than 730,000 PAYE refunds went unclaimed last year, with the average repayment worth approximately £855.  PAYE overpayments can arise for...

Loans to directors: tax rate increased

Loans to directors: tax rate increased

An outstanding loan to a director or shareholder from a close company can trigger a tax charge under Section 455 of the Corporation Tax Act 2010. The director's loan account is generally used to account for temporary withdrawals from the business for the director's...

We use contact information you provide to us to contact you about our relevant content, products, and services. You may unsubscribe from these communications at any time. For information, check out our Privacy Policy.