If you receive a letter from HMRC saying you owe tax but have never filed a Self Assessment return, you may have received a Simple Assessment. Introduced in 2017, Simple Assessment allows HMRC to calculate your tax liability and send you a bill, without requiring you to complete a full Self Assessment return.
What is Simple Assessment?
Simple Assessment (SA302-style calculation sent directly by HMRC) is used for individuals with straightforward tax affairs who are not already in the Self Assessment system. HMRC uses information it already holds, from employers, pension providers, banks, and the Department for Work and Pensions, to calculate what you owe.
You will receive Simple Assessment if HMRC determines that:
- You have underpaid tax through PAYE that cannot be collected via a tax code adjustment
- You receive the State Pension in excess of your Personal Allowance
- You have income from other sources not captured through PAYE
Simple Assessment vs P800
| Document | What it means | Action required |
|---|---|---|
| P800 (tax calculation) | HMRC thinks you have overpaid, a refund is due | Claim online or wait for cheque |
| Simple Assessment letter | HMRC thinks you owe tax | Pay within 60 days or dispute |
How to pay a Simple Assessment bill
HMRC will give you a 60-day window from the date of the letter to pay. Payment options include:
- Online via your HMRC personal tax account (www.gov.uk/pay-self-assessment-tax-bill)
- Bank transfer (BACS/CHAPS) using the reference on the letter
- Debit card online
- Cheque payable to "HM Revenue and Customs"
How to dispute a Simple Assessment
If you think the calculation is wrong, you can challenge it within 60 days of the date on the letter. Common reasons to dispute:
- HMRC has incorrect income figures (e.g., used gross rather than net pension income)
- You have allowances or reliefs that HMRC was not aware of
- The State Pension figure used is incorrect
Contact HMRC by phone (0300 200 3300) or in writing. Keep a copy of all correspondence.
Does Simple Assessment replace Self Assessment?
No. If your tax affairs are complex, for example, you have rental income, are self-employed, or have capital gains, you still need to register for and complete a Self Assessment tax return. Simple Assessment is only suitable for individuals with straightforward, PAYE-based income.
Frequently asked questions
Can I ignore a Simple Assessment letter?
No. If you do not pay within 60 days, HMRC will charge interest and may issue penalties. If you disagree with the amount, dispute it, but do not simply ignore the letter.
What if I cannot afford to pay the Simple Assessment amount?
Contact HMRC before the 60-day deadline to discuss a Time to Pay arrangement. HMRC can spread the payment over several months, though interest will accrue on the outstanding balance.
Will I get Simple Assessment every year?
Not necessarily. If HMRC can correct an underpayment through your PAYE tax code in the following year, it will usually do so rather than send a Simple Assessment. You are more likely to receive Simple Assessment if the underpayment is too large to collect through a code adjustment within a single year.