Every HMRC letter, explained

Last reviewed 1 October 2026 · How Tax Letters checks its facts

HMRC sends some letters to millions of people every year, and others in smaller campaigns, thousands at a time, when its data suggests something may need checking. Start with the letters most people get; the campaign tracker follows. If your letter is not here, it may be routine rather than a campaign: see the routine letters, or paste it into the checker.

The letters most people get

P800 tax calculation HMRC's end-of-year calculation for people taxed through PAYE: it shows a refund or an underpayment, with the working.
Simple Assessment (PA302) HMRC's calculated bill for tax it says you owe, sent instead of a tax return, with a 60-day window to query the figures.
Tax code notice (P2) The notice that sets how much tax PAYE takes. No deadline, but a wrong code takes wrong tax every payday.

Got a Simple Assessment (PA302)? Beyond the guide, it has its own tool: check its figures against your records.

Compliance campaigns

Campaigns are the one-to-many letters HMRC sends when third-party data suggests something to check. Practitioner trackers exist for accountants; this one is written for the person holding the letter. Campaigns with a full guide are marked.

Every HMRC letter, explained

The letters most people get

Compliance campaigns

For individuals

For businesses

Sent to tax agents