What is a P800 tax calculation?
Answered 11 March 2026
HMRC Guidance / Practice
A P800 Tax Calculation is a document issued by HMRC to PAYE taxpayers (i.e. those not in Self Assessment) following an end-of-year reconciliation of their tax position. Here is what the sources tell us:
What it is and when it is issued
- The P800 is issued as part of the end-of-year PAYE reconciliation process. HMRC's NPS(PAYE) system conducts this reconciliation and, where appropriate, issues a P800 Tax Calculation to the taxpayer.
- A P800 is only issued if the overall result is a PAYE underpayment or overpayment of tax. It will not be issued where the overall result balances exactly.
- It identifies whether a tax debt has been collected or not.
Overpayments and underpayments
- Where the P800 shows an overpayment, it is issued at the same time as the repayment.
- Where the P800 shows an underpayment, it is issued up to 2 days after approval, and the underpayment may be collected through the tax code or, in some cases, via Simple Assessment (PA302).
- The P800 includes reasons explaining why the customer has overpaid or underpaid tax.
Multi-year reconciliations
- In a multiple year reconciliation, up to 4 P800 calculations can be co-enveloped and issued together.
- A P800 is not issued for any year that is "Reconciled – Balanced" within a multiple year reconciliation.
- The final P800 from a multi-year reconciliation includes a tax history on the last page, covering overpayments, underpayments, balanced results, and whether the customer was in SA.
Relationship with PA302
- Where an underpayment cannot be collected through the tax code, a PA302 (Simple Assessment) is issued instead of a P800.
In summary, a P800 is HMRC's informal tax calculation sent to PAYE taxpayers after the end of the tax year to notify them that they have either overpaid or underpaid income tax, explaining the reasons and setting out what will happen next (either a repayment or collection of the underpayment).
Citation sources
rocess and you will need to review the tax calculations (PAYE96220) for all relevant years before you either Approve them for issue (PAYE96225) Or Amend (PAYE96230) and then approve them for issue Or Cancel them (PAYE96235) Where it is not possible to perform a multiple year reconciliation (for example where CY-4 is being reconciled but CY-3 cannot be reconciled as an expected P14 or ‘End of Year’ (EOY) Record information for the year is outstanding) or the reconciliation only covers CY-1, the s
Where a particular year within a multiple year reconciliation is ‘Reconciled - Balanced’ and you select the Approve Multiple Tax Calculation action link in the Multiple Year Reconciliation screen, although a copy of the calculation will be retained on the system to allow you to view it at a later date, a Tax Calculation (P800) in respect of the year concerned will not be issued to the customer. For example, in a multiple years reconciliation covering years CY-3 to CY-1, if CY-3 is ‘Reconciled -
To view the overpayment reasons printed on a Tax Calculation (P800) that has already been issued or, where the calculation concerned has a status of ’Pending’ (issue), you access the overpayment reason screens by selecting the [P800 Reasons] button on the appropriate Tax Calculation screen. In a case where your review indicates that the overpayment reasons recorded on the system are incorrect, where the tax calculation Has already been issued, you cannot alter the reasons already printed / to be
Where a Tax Calculation includes an underpayment or overpayment from an earlier year and / or it includes an underpayment or overpayment to be carried forward to a later year and you need more information about the amount concerned, you will need to review the customers Accounting (PAYE98000) records. Customers’ tax history is now detailed on the last page of the final P800 from a multi-year reconciliation. The history will include over and underpayments, balanced results and if the customer was
Some content of this manual is being considered for archiving. If there is content you use regularly, please email hmrcmanualsteam@hmrc.gov.uk to let us know as soon as possible. NPS(PAYE) conducts the end-of-year reconciliation and will determine if all the debt has been collected. NPS(PAYE): updates accounting entries onto the customer’s PAYE account updates the Contact History on the customer’s PAYE account sends to NPS(NI), details of amounts collected in the form of a credit to the receiva
The Tax Calculation field displays whether the calculation is ‘Issued’ ‘Pending’, ‘Blank’ or ‘Cancelled’. To determine this, the system will look at the status of the tax calculation. This will either be a P800 or PA302. It will take up to 2 days for the P800 or PA302 to be issued for underpayments, see PAYE93045. P800 for overpayments will be issued at the same time as the repayment, see PAYE93040.
NPS(PAYE): conducts in-year reconciliation if there is a change of circumstances; for example, a cessation case sends to the Head of Duty (HoD) system details of amounts collected in the form of a credit adds accounting entries onto the customer’s account updates the Contact History conducts the end-of-year reconciliation and will determine if all the debt has been collected issues a P800 Tax Calculation to the customer, where appropriate. NPS(PAYE) in-year reconciliation will: prioritise amount