HMRC to Send 1.8 Million Simple Assessment Letters for 2025/26

HMRC Sending 1.8 Million Simple Assessment Letters: What Taxpayers Need to Know

HMRC is issuing around 1.8 million Simple Assessment letters for the 2025/26 tax year, with many taxpayers already receiving notifications and a further round due to be sent between October and December 2026.

If you receive a Simple Assessment letter, it's important not to ignore it. The notice explains how much tax HMRC believes you owe and when payment is due. However, the calculation is based on information HMRC holds and, in some cases, mistakes can occur.

What is a Simple Assessment?

A Simple Assessment is used when HMRC cannot collect the correct amount of tax through PAYE and the taxpayer is not required to complete a Self Assessment tax return.

Common reasons for receiving a Simple Assessment include:

• Tax due on pension income
• Untaxed savings interest
• Dividend income
• A second source of income that has not been fully taxed
• Receiving more personal allowance than you were entitled to
• Tax liabilities that cannot be collected through a tax code, typically where more than £3,000 is owed

HMRC sends a PA302 Simple Assessment letter outlining the calculation and the amount due.

Important Payment Deadlines

The deadline for paying a Simple Assessment depends on when you receive the letter:

• Letters received before 31 October 2026: payment is due by 31 January 2027
• Letters received on or after 31 October 2026: payment is due within three months of the date on the letter

Taxpayers may be able to pay in full or arrange instalments, depending on their circumstances.

Why You Should Check the Calculation Carefully

While HMRC's calculations are based on information provided by employers, pension providers, banks and other third parties, the data used may not always be complete or accurate.

Before making payment, you should review the assessment against your own records and check that:

• All income figures are correct
• Personal allowances have been applied correctly
• Any pension, savings or dividend income has been reported accurately
• The assessment genuinely relates to income that has not already been taxed

If you believe the calculation is incorrect, you should contact HMRC as soon as possible.

How Charlton Baker Can Help

Receiving an unexpected tax demand can be worrying, particularly if you're unsure how HMRC arrived at the figure or whether the assessment is correct.

Our tax specialists can review your Simple Assessment notice, explain the calculation, identify any errors and advise on the most appropriate course of action. We can also help with wider tax planning opportunities to ensure your affairs are structured as tax-efficiently as possible going forward. Give our expert team a call on 01380 723692 or email here.