How to Claim a Tax Refund From HMRC: Every Route, Step by Step

The question people actually type is "how do I claim my tax refund". The honest answer is that it depends entirely on why you overpaid, and HMRC has a different door for each reason. Someone who got a P800 in the post has a five-minute job. Someone who has been on a BR code for two years has never had a letter and never will, and has a slightly longer job. Someone claiming for washing a uniform is on a third route again.

Pick the wrong door and the claim goes nowhere. This guide sorts you into the right one in about a minute, then walks the route end to end with the current 2026/27 figures.

Every number here is an estimate based on published rates and thresholds. Confirm your own position with HMRC before you act on it.

Step 1: find your route

Work down this table and stop at the first row that describes you.

If two rows apply, do them in order. A wrong code and an unclaimed uniform allowance are separate claims that can both be running at once.

Route 1: your P800 says you are due a refund

A P800 is HMRC's own end-of-year reconciliation. HMRC's guidance on tax overpayments and underpayments states the letters "are sent out between June and March of the following tax year", and that you only get one if you are employed or receive a pension.

Read the letter before you claim. The income figures on it come from your employers and pension providers, not from HMRC's own knowledge, so a stale employer record produces a confident, wrong calculation. Check each employment listed against the P60 or final payslip for that job.

Then claim. According to HMRC's guidance for people due a refund, you will need the reference number from the P800 and your National Insurance number, and the timings are:

Two details worth knowing. You can also claim through your personal tax account or the HMRC app if you have a UK bank account. And if you are owed tax for more than one year, HMRC says you will get "a single cheque for the entire amount", so do not wait for several payments.

If the figures on the letter look wrong, do not claim and hope. HMRC's instruction is to contact them and "tell HMRC which amounts you think are incorrect and what they should be".

Route 2: no letter, and the code on your payslip is wrong

This is the biggest silent category. A P800 is only generated where HMRC's records flag a discrepancy. If the wrong figure was in the records all along, for example a company car that ended in 2024 and was never removed from your code, the year reconciles cleanly to the wrong answer and no letter is produced. Nobody tells you.

For the tax year currently running, you do not make a claim at all. You correct the code, and the money comes back through payroll.

1. Sign in to Check your Income Tax for the current year. This service covers 6 April 2026 to 5 April 2027.
2. Read your current code and compare it with your latest payslip. If they differ, your employer has not applied the newest code yet.
3. Open the breakdown of how HMRC built your allowance, and read every deduction. Stale company cars, ended medical cover, an inflated estimate of untaxed interest and old underpayments already settled are the usual suspects.
4. Check the jobs and pensions listed. A job you left should not still be producing income. A second job you never started should not be there.
5. Update whatever is wrong. HMRC's guidance is explicit that you can "update details of your income from jobs and pensions", and warns "you may pay too much or too little tax if they're not up to date".
6. Wait for the P2 coding notice, then check the next payslip actually uses the new code.

Our tax code checker will tell you in about thirty seconds whether the code you are on matches your circumstances, and roughly what the gap is worth per year, before you log in to HMRC. It is an estimate to arm you with a number, not a replacement for HMRC's own figures.

Route 3: no letter, and a previous year looks wrong

Completed years have their own service: Check your Income Tax for previous years. HMRC describes it as a service you can use "to get a tax refund or pay tax you owe" for a year already calculated.

Open the year, read HMRC's calculation, and compare it against your P60 and payslips for that year. Where they disagree, contact HMRC with four things: the tax year, the employer, the figures you hold, and what you believe the correct position to be. Vague claims stall. Specific ones do not.

The four-year limit matters here. The general time limit for a tax claim is four years from the end of the tax year concerned, which HMRC's Self Assessment Claims Manual traces to TMA 1970 s43. As at August 2026 that leaves 2022/23, 2023/24, 2024/25 and 2025/26 all claimable, and 2022/23 closes on 5 April 2027.

Our full guide to reclaiming overpaid tax walks the whole multi-year recovery, including how to read a P800 line by line.

Route 4: money you spent to do your job

Employment expenses are a different claim with a different form, and people conflate them with tax code corrections constantly.

If you are employed and paid for something your job required, you may be able to claim tax relief on it. The main categories are working from home, uniforms and work clothing, small tools, professional fees and subscriptions, and business mileage in your own vehicle. You claim through HMRC's online expenses service or by post on form P87. If you file Self Assessment, HMRC's instruction is that "you must claim through your tax return instead".

Two important limits, both from HMRC's own guidance:

• Working from home relief has stopped for the current year. The working at home page now states: "From the tax year 6 April 2026 to 5 April 2027, you will not be able to claim tax relief for working from home. You can still claim for the 4 previous tax years." Our guide to claiming working from home tax relief covers what that means for backdated claims.
• Uniform and tools relief is a flat rate, not a refund of your spending. HMRC's flat rate expenses guidance sets an agreed fixed amount per job, defaulting to £60 where your job is not listed, and explains that "if you claim a flat rate expense of £60 and pay tax at a rate of 20% in that year, you will pay £12 less tax". See our guides to the uniform tax rebate and tools and union fees.

Expenses claims reach back the same four years, so an unclaimed trade allowance is usually five years of relief in one submission.

Route 5: you file a Self Assessment return

If you are registered for Self Assessment, HMRC states your bill "will be adjusted automatically if you've underpaid or overpaid tax" and you "will not get a tax calculation letter or a Simple Assessment letter". No P800 is ever coming.

Your refund route is the return itself. File it, and where the return produces an overpayment you request the repayment from your Self Assessment account. This is the route for CIS subcontractors, whose 20% deductions are advance payments that very often exceed the final bill.

If your self-employed income is heading over £50,000, note that Making Tax Digital for Income Tax began in April 2026, with lower thresholds following in 2027 and 2028. Our guide to MTD for sole traders sets out who is in scope and when.

Route 6: the situation-specific forms

Some overpayments have a dedicated form because the ordinary PAYE machinery cannot see them coming.

For leavers, HMRC's own note is that you "do not need to fill in this form if you are sending a Self Assessment tax return for the tax year that you leave the UK". Our guide to leaving the UK and the P85 explains why leavers are almost always owed something.

Pension lump sums are the other reliable overpayment. The first payment from a pot is usually taxed on a month 1 basis as though you were going to take that amount every month, which produces a large, temporary overdeduction.

What to have ready before you start

Missing paperwork is the main reason claims stall rather than fail. Gather this first.

• Your National Insurance number
• A P60 for each tax year in question, and a final payslip or P45 from any job you left
• The P800 reference, if you have a letter
• The dates any benefit in kind started and ended
• Receipts, only if you are claiming actual costs rather than a flat rate
• A Government Gateway user ID. If you are creating one, HMRC may ask you to confirm your identity, which it says "usually involves using photo ID like a passport or driving licence"

Your employer must give you a P60 by 31 May each year. If you have lost one, HMRC's guidance is to ask your employer for a replacement, or use your personal tax account or the HMRC app to find the same information.

A worked example: what a real claim looks like

Priya is employed on £31,000. She started the job in July 2024 without handing over a P45, so her first four months ran on an emergency M1 code. Her employer also reported a health insurance benefit that ended in March 2025, which stayed in her code through the whole of 2025/26.

Nothing there generated a letter. Two of the three years needed her to open the previous-years service and ask. That is the ordinary shape of a real claim, and it is why "have I had a P800?" is the wrong test for whether you are owed money.

Run your own year-by-year numbers with the tax code checker, then confirm the final position with HMRC.

Why claims stall, and how to stop yours

• Claiming on the wrong route. A P87 will not fix a wrong tax code, and a code correction will not reach a completed year.
• No specifics. "I think I paid too much in 2023/24" gets a slower answer than "my P60 shows £4,120 tax deducted, HMRC's calculation shows £4,940, the difference is the company car I returned on 12 June 2023".
• Chasing too early. HMRC publishes a check when you can expect a reply tool, updated weekly, covering Income Tax, Self Assessment, PAYE and CIS. Check there before you call.
• A refund company already in the way. If you ever signed with one, a nomination may still be routing your money to them. Our guide to refund companies and their fees explains how that works and what changed in the 2023 rules.

Doing it yourself versus paying someone

Refund companies are legitimate and some people genuinely prefer to hand the paperwork over. Know the price first. RIFT, one of the larger UK operators, publishes a fee of "36% of your refund (including VAT), with a minimum fee of £60" for a PAYE rebate. On a £625 refund that is £225 of your own money.

Every route on this page is free through HMRC. If a firm tells you a claim can only be made through them, that is not correct.