HM Revenue and Customs (HMRC) automatically do a Simple Assessment if you owe tax they can’t collect through your PAYE tax code vi your employer or pension and you aren’t registered for Self Assessment.
They work out what you owe then write to tell you how much this is and when you need to pay it by.
How does HMRC get this information?
HMRC usually works out Simple Assessments using information they get directly from the likes of employers, pension providers, the Department for Work and Pensions, banks, and building societies.
They can also carry out a Simple Assessment using data they get from customers or their agents – such as dividend income of £10,000 or less.
Some reasons you might get a Simple Assessment
• You owe Income Tax that HMRC can’t automatically take out of your income
• You owe HMRC £3,000 or more
• You have to pay tax on your State Pension
• You owe tax on bank or building society interest
What to do if you get a Simple Assessment letter
1. Check your tax calculation to make sure it’s right and includes all your income, deductions, and allowances for the tax year.
2. If you think the Simple Assessment is wrong, you have 60 days to query this from the date HMRC issued it.
3. You need to pay the Simple Assessment by date shown on the letter, usually 31 January or three months from the date HMRC issued it.
You can also pay tax by signing into your online tax account:
PAYadvice.UK 29/6/2025