HMRC & tax · UK guide · 2026

Got a P800? It's Either Money Back or a Small Bill — Here's Which, and What to Do.

Last verified 16 Jul 2026 · Source GOV.UK / HMRC · Information, not legal advice · Publisher: CA Capital Limited (company no. 10848369)

A P800 is HMRC's end-of-year sums: the tax you actually paid versus the tax you should have paid. Millions go out every summer. Yours says one of two things — you overpaid (refund due) or you underpaid (usually collected gently through next year's tax code). Neither is a penalty. Here's how to claim the refund fast, what an underpayment really means, and the scam texts to delete on sight.

Refund Due? Claim It Online — It's Faster

If your P800 says you overpaid, the quickest route is your Personal Tax Account at GOV.UK or the HMRC app: request the refund to your bank account and it typically lands within days. If you don't claim online, HMRC usually posts a cheque instead — which works, but takes noticeably longer. Your letter tells you which applies.

Common causes of overpayment: changing jobs mid-year, an emergency tax code, working only part of the year, or workplace expenses you're owed relief on — our tax refund guide covers reclaiming for earlier years too.

Owe Tax? It's Usually Collected Painlessly

For most people in PAYE, an underpayment is collected automatically through next year's tax code — a small adjustment spread over twelve months, no action needed. Your code will change (see our tax code guide to read it), and that's it.

If it can't be coded out — the amount is too large, or you're no longer in PAYE — HMRC sends a Simple Assessment (PA302) asking for direct payment. That letter has its own deadline and its own guide.

Don't Just Accept It — Check the Figures

  • Compare the income and tax-paid lines against your P60 (or P45 if you left a job) — our guide to each form.
  • Check benefits-in-kind (company car, medical insurance) against your P11D.
  • Check any savings-interest estimate against your bank's annual summary.
  • Confirm the same calculation appears in your Personal Tax Account — that also proves the letter is genuine.

If something's wrong, contact HMRC with the correct figures — calculations get corrected routinely.

The P800 Scam Wave — Delete on Sight

Every P800 season brings a flood of fake "you have a tax refund" texts and emails. The rule is absolute: HMRC does not send refund links by text or email. A real P800 arrives by post and matches your Personal Tax Account. Anything else goes straight to our scam checker — and to HMRC's phishing inbox (phishing@hmrc.gov.uk).

P800 — Quick Answers

Is a P800 a fine? No — it's a reconciliation. Even the "you owe" version is just the sums balancing out.

Do I need to do Self Assessment now? No — a P800 is specifically for people not in Self Assessment.

Not sure what your letter is? Upload it to the letter decoder — it identifies the letter, pulls out any deadline, and saves it to My cases with a reminder.

Refund? Claim it today. Bill? Check it, then let PAYE handle it.

Five minutes with your P60 settles whether the sums are right — and the refund is usually days away once you claim online.