Your situation
P800 tax calculation letter
HMRC's year-end check on employees and pensioners: what the letter compares, why it arrives and how each outcome is settled.
Overpaid tax and how it comes back
Overpaid
£714
| Tax due with 1257L | £3,486 |
| Refund online | 5 working days after claiming |
| Refund by cheque | within 6 weeks |
Employment income in England, Wales or Northern Ireland with the standard allowance.
A P800, also called a tax calculation letter, is the result of HMRC's check once a tax year has closed on 5 April: it compares the Income Tax taken through PAYE with the tax due on your full income, as described on GOV.UK. Only employees and pension recipients receive one, and the letters are sent between June and March of the next tax year. People in Self Assessment never get a P800, because their return already corrects the figure. If you earned £30,000 from one job in England and payroll took £4,200.00, the tax due with the standard allowance is £3,486.00, so the letter would show £714.00 overpaid. A refund claimed online arrives within 5 working days. A debt under £3,000 is usually taken through your code over 12 months from the next April; larger sums, or tax that payroll cannot collect, come as a Simple Assessment letter instead.
Owed tax collected through your code
Code next tax year
1032L
| Allowance taken off | £2,250 |
| Extra each month over 12 | £37.50 |
| Limit for coding out | under £3,000 |
HMRC reduces the code by the amount owed divided by your rate, so the extra tax adds up to the debt.
Rules read on HMRC’s texts by Radif Partners · Editorial policy · Method
What the letter compares
Your employers and pension providers report every payment to HMRC, together with the tax they deducted. After the year closes, HMRC adds the reports up, along with income from the benefits office, and recalculates the tax on the total using your real allowances. The P800 sets the two numbers side by side: tax due on one line, tax paid on the other, and the gap between them.
The check only concerns people taxed through PAYE. If you are registered for Self Assessment, an under- or overpayment is absorbed by your return and no tax calculation letter is sent. If you think the PAYE figures for the current year are drifting, the Check your Income Tax service shows the estimate HMRC is working from before the year ends.
Reasons a P800 is sent
GOV.UK gives four typical triggers, and each one is a code problem at heart:
- a wrong tax code, often because HMRC held the wrong income figures;
- leaving one job and starting another, with both paying you in the same month;
- a workplace pension starting during the year;
- Employment and Support Allowance or Jobseeker's Allowance received during the year.
When a P800 is not possible, a Simple Assessment letter takes its place: for tax that cannot be taken automatically from your income, for debts above £3,000, and for tax on the State Pension that could not be collected through another code, as the State Pension guidance confirms.
How each outcome is settled
| Outcome on the letter | What happens |
|---|---|
| Refund, letter invites an online claim | within 5 working days by bank transfer |
| Refund, you request a cheque online | within 6 weeks |
| Refund, letter says a cheque is coming | within 14 days of the letter's date, no claim needed |
| Debt under £3,000, enough PAYE income | lower code, 12 equal monthly instalments from the next April |
| Debt that cannot be coded | HMRC writes with other ways to pay |
For an online claim you need the reference number on the letter and your National Insurance number. With a UK bank account you can also claim through your personal tax account or the HMRC app. Where you are owed for several years, an automatic cheque pays it all at once. The refund guide shows how much of the same money could have come back earlier through payroll.
Owed tax collected through your code
Code next tax year
1032L
| Allowance taken off | £2,250 |
| Extra each month over 12 | £37.50 |
| Limit for coding out | under £3,000 |
HMRC reduces the code by the amount owed divided by your rate, so the extra tax adds up to the debt.
When the P800 shows tax owed
A debt is usually recovered without a payment from you. HMRC changes your code for the following tax year so that your employer or pension provider deducts a little more each month, normally in equal instalments over 12 months. Three things must be true: you pay Income Tax through PAYE, your income above the Personal Allowance is large enough, and the debt is under £3,000. A basic rate payer owing £450 would see £2,250 come off the allowance, taking 1257L to 1032L; the underpaid tax page shows the effect for other amounts and rates.
You do not have to accept the slower route. GOV.UK allows you to pay the sum before the next tax year begins, which keeps your April code clean. If the letter is wrong rather than simply unwelcome, contact HMRC with the amounts you dispute and the figures you believe are right; it either sends a corrected calculation or explains why the original stands.
If no letter arrives
No P800 may mean HMRC found nothing to correct, or that your letter has not been sent yet within the June to March window. If you are confident you overpaid on a job or pension, HMRC's refund checker points to the right claim. If you suspect you underpaid and nothing has come, GOV.UK asks you to contact HMRC instead of waiting for a letter.