We explain p800 tax calculations in plain English, handle it correctly, and make sure you claim every relief you are entitled to, all at a fixed fee.
P800 Tax Calculations
A P800 is the calculation HMRC sends when they think you have paid too much or too little tax through PAYE, but these calculations are not always right, they can be based on incomplete or wrong information, so it is worth checking before you accept a bill or a refund.
We check your P800 against your actual income and circumstances, confirm whether it is correct, challenge it where it is wrong, and make sure you claim any refund you are owed or dispute any underpayment that should not stand.
HMRC's P800 calculations rely on the information they hold, which can be out of date or incomplete, so they sometimes show a refund that is too small, or a bill that is not actually due, making an independent check valuable.
The Detail That Matters
A P800 is the calculation HMRC sends when it thinks you have paid too much or too little tax through PAYE. These calculations are not always right, based on incomplete or wrong information, so it is worth checking before accepting a bill or a refund.
HMRC issues a P800 after the tax year when its records suggest you overpaid or underpaid through PAYE, showing a refund or an amount owed. It is generated automatically from the data HMRC holds.
P800s rely on employer and pension data and HMRC's estimates, which can be out of date or incomplete, so the refund can be too small, or a bill shown that is not actually due.
We check the P800 against your actual income, expenses, benefits and allowances, confirming whether the figures are right before you accept a bill or bank a refund.
Where it is wrong, we challenge it with HMRC and correct the figures; where a refund is due, or a larger one than shown, we make sure you receive everything you are owed.
People accept a P800 bill or refund without checking, but HMRC's figures can be wrong in either direction, leaving you overpaying, or missing part of a refund you were entitled to.
Key Figures
How We Help
We check your P800 against your real income, expenses and allowances, confirming whether the calculation is actually correct.
Where the P800 is wrong, based on incomplete or incorrect information, we challenge it with HMRC and put the figures right.
Where a refund is due, or a larger one than shown, we make sure you receive everything you are owed.
All the forms, calculations and correspondence handled on your behalf, so you never have to decode HMRC's rules or sit on hold.
A clear fixed fee quoted after a free call, your position explained in plain English, and never a surprise bill.
We act quickly, and where earlier years are involved we put those right too, reclaiming refunds or minimising penalties.
People often accept a P800 bill or refund without checking, but HMRC's figures can be wrong in either direction. An independent check makes sure you neither overpay nor miss a refund, and we do it for you.
Recent Client Outcome
A client received a P800 showing they owed tax, but it did not match their understanding of their income.
What we did. We checked the calculation against their actual income and allowances, found HMRC had used incomplete information, and challenged it.
The outcome. The corrected figures removed the underpayment and in fact produced a small refund instead.
Checking the P800 rather than accepting it turned a bill into a refund, because HMRC's data had been wrong.
Why People Come to Us
Questions Answered
Want us to handle this for you, end to end?
See our Self-Assessment Accountant →Free fifteen-minute call. Fixed quote within twenty-four hours. Your return filed, every expense claimed, your bill explained, and salon VAT, payroll and accounts handled if you own a salon. Same accountant, start to finish.
Or email info@yourtaxhelp.co.uk, we typically respond within two business hours.
📅 Free consultation calls available weekdays 1pm to 3pm and 7pm to 8pm. Pick a slot that suits you.