At 7.04am on a Tuesday, Leanne’s phone buzzed on the bedside table in Wigan. “HMRC: you are owed £412.60. Claim within 48 hours.” She nearly tapped the link. Three weeks later a brown envelope on the doormat said she really was owed money, a different amount, with no link. That gap between the fake text and the real letter is where people get confused, so here is how to claim a tax refund online with HMRC, what the letter means, and which messages to ignore.
Claiming a Tax Refund Online at a Glance
| Who it’s for | Employees and pensioners who overpaid through PAYE, plus work expenses and taxed pension lump sums |
| Where to claim | Personal tax account, the HMRC app, or the GOV.UK refund service |
| What you need | National Insurance number, your P800 reference, and a UK bank account |
| How long it takes | 5 working days online, 6 weeks for a requested cheque, 14 days for an automatic cheque |
| How far back | 4 years: the oldest year still open is 2022/23, which closes on 5 April 2027 |
| Cost | Free. HMRC never charges to pay you back |
| Helpline | 0300 200 3300, Monday to Friday, 8am to 6pm |
Who Can Actually Claim Money Back
Leanne is a healthcare assistant. In May 2026 she left an agency job, started at a care home in June, and was paid by both employers in the same month. That is one of the situations HMRC lists as a reason for a tax calculation letter, alongside being put on the wrong tax code, starting a workplace pension, and receiving Employment and Support Allowance or Jobseeker’s Allowance. You only get one if you’re employed or drawing a pension; Self Assessment filers have the return corrected instead. Work expenses and taxed pension lump sums are claimed separately. If a payslip figure looks odd, first understand what your tax code actually means before deciding you’ve overpaid.
The P800 Letter and What It Asks You to Do
The brown envelope is a P800, posted between June and March of the following tax year. For the year that ended on 5 April 2026, GOV.UK says you should have yours by 30 November 2026 if a refund is due. It comes in two flavours. One says you can claim online, using the reference printed on it plus your National Insurance number. The other says a cheque is on its way and you do nothing: it arrives within 14 days of the date on the letter. Owed for several years? One cheque covers the lot. A Simple Assessment letter is usually a bill, with 60 days to challenge it. The wording sits on the official GOV.UK page on P800 refunds, the only place a P800 tax calculation should ever send you.
Claiming Through Your Personal Tax Account or the HMRC App
Leanne’s letter said she could claim online, so she sat at the kitchen table and signed in. New to this? Start by reading how to set up a Government Gateway account, because the same sign-in details open both the personal tax account on GOV.UK and the HMRC app. In the app you open the Pay As You Earn section, check the income HMRC holds for the year, add anything missing, and press the refund button when it appears. HMRC only pays into a UK bank account, and an online claim is paid within 5 working days. The app, used by more than 5.9 million people according to HMRC’s last annual report, opens with a PIN, fingerprint or face scan. Leanne’s money landed on the Friday.
Still in the Job? The Refund Comes Through Your Payslip
Her colleague Marcus had a different problem. He started in April, HMRC didn’t have his new income details, and too much tax was coming off every month. For that there is no letter and no form. HMRC explains that once your tax code is corrected, your employer gives you the refund in your pay, normally the first payday after the new code arrives. So the fix is to sign in, check your tax code online, and update your employment details if a job is missing or an old one is still listed. An emergency code often shows as 1257L with W1, M1 or X after it. Marcus updated his details one Sunday and saw the money in his next wage slip.
Left a Job or Stopped Working Altogether
Leanne’s mum retired in July and isn’t taking a pension until next year. With no payslip, HMRC can’t refund her through one. You can claim online through the GOV.UK tool or post form P50, but only once you’ve had your final pay and finished the job more than 4 weeks ago. You must also expect no new job or workplace pension before 5 April, and not be on Jobseeker’s Allowance, Employment and Support Allowance, Carer’s Allowance or long-term Incapacity Benefit. HMRC then posts a cheque, or payable order, within 5 weeks of processing. Wait 14 days before chasing the application and 5 weeks before chasing the money. Pension lump sums use their own P55, P53Z and P50Z forms, normally paid within 30 days.
Work Expenses and the P87: Small Claims That Add Up
Back on the ward, Leanne learned that washing her own uniform counts too. Employees can claim tax relief on things they must buy for the job and use only for work, if the employer doesn’t pay them back. Agreed flat rates need no receipts: £60 for most jobs, £125 for nurses, midwives and healthcare assistants, £140 for police officers and joiners, and £80 for firefighters. Relief is the rate times your tax band, so £60 at 20% is £12 back, and Leanne’s £125 is worth £25 a year. You can claim for the current year and the 4 before it, online through GOV.UK or on the paper form known as the P87 expenses claim. Claim more than the flat rate and you must post receipts. Self Assessment filers use the return.
How Far Back You Can Go: The 4-Year Rule
Leanne’s brother Dev asked the question everyone asks: can I go back years? Yes, but not forever. The GOV.UK refund tool offers four choices: on or after 6 April 2026, the year to 5 April 2026, the three years from 6 April 2022 to 5 April 2025, and before 6 April 2022. Pick that last one and the screen says you cannot reclaim anything from before April 2022. That makes 2022/23 the oldest year still open, and it shuts on 5 April 2027. For older years, sign in to your personal tax account, check the tax paid each year, and send HMRC an update for each year that looks wrong. Refunds usually arrive within 3 weeks. Dev first had to fix his lost Government Gateway user ID.
Refund Texts, Emails and the “Refund Companies”
Back to that 7.04am text. HMRC does send texts, but only with links to GOV.UK information or webchat, and it says not to open any link offering a refund in return for personal or bank details. Genuine emails come only from addresses ending hmrc.gov.uk, and HMRC does not send refund details by email. Forward a dodgy text to 60599 or email phishing@hmrc.gov.uk, then delete it; if you’ve lost money, call Report Fraud on 0300 123 2040. Check the signs of an HMRC text scam against HMRC’s scam checklist. Refund companies are legal but unconnected to HMRC, and they keep a fee. Since 15 March 2023 they cannot take an “assignment” of your refund, and since 6 April 2025 a paid agent on a P87 needs your advanced electronic signature. A nomination can be cancelled before payment.
Where This Leaves Leanne
Leanne ignored the text, claimed from the letter, and had her refund in under a week. Her brother went back to 2022/23 before that door closes next April. None of it needed a company, a fee, or a link in a message. To claim a tax refund online with HMRC you need your sign-in, your National Insurance number, and a few quiet minutes. Log in this week, check the last four years, and keep what is already yours.
Frequently Asked Questions
How long does an HMRC tax refund take?
An online P800 claim is paid within 5 working days. A requested cheque takes up to 6 weeks, and an automatic cheque arrives within 14 days of the letter date.
How far back can I claim a tax refund from HMRC?
Four years. As of August 2026 the oldest year still open is 2022/23, and the deadline for that year is 5 April 2027.
Will HMRC refund me automatically without a claim?
Sometimes. If your P800 says a cheque is coming, you do nothing and it arrives within 14 days. If it says claim online, you must sign in and request it.
Is the HMRC tax refund text message real?
Almost never. HMRC texts only link to GOV.UK information or webchat and never ask for bank details to pay a refund. Forward the message to 60599 and delete it.
Do I need a company to claim my tax refund?
No. Claiming through your personal tax account or the HMRC app is free, while refund companies keep part of your money. Any nomination can be cancelled before payment.
Disclaimer: This article is general information, not financial or tax advice. Rules, timings and flat rates come from GOV.UK and were correct as of August 2026; check the official HMRC pages for your own situation before making a claim.