Starting in June 2025, HMRC will begin issuing Simple Assessment letters outlining the amount of tax owed on income received between April 2024 and April 2025.
These letters are sent to individuals not registered for Self Assessment, typically when:
- They do not have a PAYE tax code, or
- HMRC is unable to collect the tax owed through PAYE.
Why Clients May Be Contacting You
While some people may receive a Simple Assessment regularly, most will be unfamiliar with it—how it’s calculated, why they’ve underpaid tax, or what action they need to take. You may start receiving questions from clients as a result.
What the Simple Assessment Letter Includes
Each letter will provide:
- The total tax owed
- The payment deadline (usually by 31 January)
- Instructions on how to pay, and what to do if the customer disagrees with the calculation
Customers can pay in a number of ways, including through the HMRC app. More information is available on GOV.UK under "Pay your Simple Assessment tax bill."
Common Reason: State Pension
A frequent reason for receiving a Simple Assessment is to settle tax owed on the State Pension. Customers can use HMRC’s online tool to check whether they need to pay tax on their pension.
Helpful resources include:
- Video: How increases to the State Pension can affect the tax you pay
- Video: How to pay tax due on your State Pension if it exceeds your Personal Allowance
(If videos are unavailable due to cookie settings, customers can watch them directly on YouTube.)
Additional Assessments
If HMRC receives new information—such as untaxed interest from banks or building societies—a customer may receive a second Simple Assessment for the same tax year. These assessments are treated separately, and the amount due on the second is in addition to the first.
Already Filed a Tax Return?
If a customer has already filed a Self Assessment tax return for the same tax year, or is registered for Self Assessment, they (or their agent) should call HMRC on 0300 200 3300 to have the Simple Assessment withdrawn.
