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What an HMRC PA302 Simple Assessment means

A PA302 is HMRC’s Simple Assessment tax bill. It usually means HMRC thinks you underpaid Income Tax for a past tax year and could not collect it through your PAYE tax code. It is not the same as filing a Self Assessment return. Always check the figures on your letter or Personal Tax Account.

General information only — not legal or financial advice, and not a substitute for an accountant. For free help, contact Citizens Advice or read GOV.UK — Understand your Simple Assessment and GOV.UK — Pay your Simple Assessment.

In plain English

After the tax year ends, HMRC reconciles information from employers, pension providers and banks. If you owe tax that could not be collected via your tax code, HMRC may send a Simple Assessment (PA302) by post or to your Personal Tax Account. The letter shows how much tax you owe, how it was calculated, and how to pay.

• Underpayment / amount due: most PA302s ask you to pay the balance by the deadline on the letter. You can usually pay in full or in smaller payments, as long as the full amount is cleared by that deadline.
• Refund / overpayment: less common on a Simple Assessment, but if HMRC’s figures are wrong and you have overpaid, follow GOV.UK guidance and contact HMRC — do not rely on text or email “refund” links.
• Payment reference: use the 14-character reference starting with X from your letter. A wrong reference can delay payment or apply it to another bill.

Deadlines and timing

1. Payment deadline: follow the date on your letter. GOV.UK explains typical rules (for example, for the 2025–26 tax year, letters before 31 October 2026 are often due by 31 January 2027; later letters may be due within three months of the letter date). Always verify on the official pages and your letter.
2. If the figures look wrong: contact HMRC within 60 days of the date on the bill, explaining which amounts are wrong and what they should be, with evidence (payslips, bank statements, pension info).
3. If you cannot pay in full: you can still make smaller payments towards the deadline, and check GOV.UK help if you cannot pay on time. Consider free debt advice early.

What to check on the letter

• Your name, National Insurance number and tax year.
• Income lines (employment, pension, savings interest, dividends) vs your P60 / statements.
• Tax already paid / deducted vs the amount now due.
• The X… payment reference and bank / online payment instructions.
• Whether this replaces an earlier Simple Assessment for the same year (pay only the remaining difference if you already paid part).

What to do next

• Confirm it is genuine HMRC correspondence — HMRC does not text or email “pay now” or “claim refund” links.
• Compare the calculation with your Personal Tax Account and paper records.
• If correct, pay by the deadline using the X reference (online, bank transfer or other methods on GOV.UK).
• If wrong, contact HMRC within 60 days with evidence.
• If you cannot afford it, seek free advice and check official “cannot pay” guidance early.

Reply sketch (edit before you send)

HM Revenue & Customs
[Address / contact from your letter]

Date: [today’s date]

National Insurance number: [NI number]
Simple Assessment / payment reference: [X…………]

Dear Sir or Madam,

I am writing about the Simple Assessment (PA302) dated [date] for tax year [year].

[Option A — figures look wrong]
I believe these amounts are incorrect: [list]. I think they should be: [list].
I checked using [P60 / payslips / bank / pension statements]. Please review and send an updated assessment.

[Option B — need time to pay]
I intend to pay what is due. I cannot clear the full balance in one payment because [brief reason].
Please confirm how I can pay by the deadline / what options are available.

Yours faithfully,
[Your name]

Common mistakes

• Treating a PA302 as a Self Assessment return you must file — different process.
• Using the wrong payment reference.
• Missing the 60-day window to challenge wrong figures.
• Clicking refund or payment links in unexpected texts or emails (scams).

Free help

• GOV.UK — Understand your Simple Assessment
• GOV.UK — Pay your Simple Assessment
• GOV.UK — If the amounts are wrong
• GOV.UK — Personal Tax Account
• Citizens Advice

More guides: HMRC P800 · HMRC debt / Time to Pay · Notice to file · All guides

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