John GreenMillions of UK workers and self-employed individuals may be owed money from HMRC following the end of the 2025/26 tax year on 5 April 2026 — but many will not receive a penny unless they actively claim it. A little-known rule change introduced in 2024 means that HMRC no longer automatically issues refunds via cheque: you must now log in and claim.
Why So Many People Are Owed Tax Refunds
Tax overpayments are more common than most people realise. They happen when your employer applies the wrong tax code, when your income changes mid-year (through redundancy, job changes, or reduced hours), when you start receiving a pension, or when you make contributions to a private pension or Gift Aid charity that haven't been reflected in your PAYE record.
According to HMRC's annual statistics, hundreds of thousands of P800 letters — the official notification that you have overpaid tax — are issued every year between June and November, following the close of each tax year. For the 2025/26 tax year, those letters will begin arriving from June 2026.
Self-employed individuals filing a Self Assessment return for the tax year ended 5 April 2026 may also be eligible for a refund if allowable expenses, pension relief, or other deductions reduce their final tax liability below their payments on account.
The Critical Rule Change: You Must Now Claim Online
Until May 2024, HMRC automatically sent tax refund cheques to those identified as having overpaid. That process has changed. Now, when HMRC issues a P800 calculation showing you are owed money, you must claim the refund yourself — online.
The process is straightforward:
- Wait to receive your P800 letter from HMRC (arriving June to November 2026 for the 2025/26 tax year)
- Log in to your Personal Tax Account at gov.uk/personal-tax-account
- Navigate to "Claim a refund"
- Enter your bank details (sort code and account number)
- Receive payment within approximately five working days
If you do not claim online within 45 days of receiving your P800, HMRC may revert to issuing a cheque — but the timeline is uncertain, and the shift toward digital-only processing means delays are increasingly common.
How Far Back Can You Claim?
HMRC allows you to claim a refund for overpaid tax going back four tax years. For claims submitted in 2026, this means you can reclaim overpayments as far back as the 2021/22 tax year (which ended 5 April 2022). The deadline for that particular year is 5 April 2026 — meaning some older claims may already have lapsed if not submitted.
If you believe you have been paying too much tax for several years and have not yet checked, now is the time to act.
Tax Refund Scams: A Growing Problem
The period following the end of the tax year — April through July — is peak season for tax refund scams. Fraudsters send emails, text messages, and even letters mimicking HMRC branding, claiming that you are owed a refund and asking you to click a link or submit bank details.
HMRC will never contact you to offer a refund via unsolicited email or text message. All genuine refund processes happen through your Personal Tax Account at gov.uk. If you receive any such communication, do not click any links and report it to HMRC's phishing team directly.
When to Get Expert Help
While many straightforward PAYE tax refunds can be claimed independently online, some situations are more complex. If you are self-employed, have multiple income sources, have recently sold a property, or have received income from shares or investments, calculating whether you are owed a refund — and how much — can be complicated.
In these circumstances, a qualified tax adviser or accountant can review your position, identify all potential reliefs and deductions, and submit a claim on your behalf. The cost of professional advice is often far outweighed by the value of the refund recovered.
For context, HMRC has also been sending refunds by cheque for some older cases even as it transitions to digital-first processes — which adds further confusion for taxpayers unsure which route to expect.
A tax adviser can also help if:
- You have received an incorrect P800 and need to dispute it
- HMRC has processed a refund but the amount appears wrong
- You have not received a P800 but believe you have overpaid
- You are a landlord or investor with deductible expenses not captured in your PAYE record
In cases involving disputed amounts or apparent HMRC errors, having a qualified professional manage correspondence can significantly speed up resolution.
Key Dates for 2026 Tax Refunds
| Date | Action |
|---|---|
| 5 April 2026 | End of 2025/26 tax year |
| 5 April 2026 | Deadline to claim overpaid tax from 2021/22 (4-year limit) |
| June–November 2026 | HMRC issues P800 letters for 2025/26 overpayments |
| Ongoing | Self Assessment refunds processed after filing |
The end of the tax year is a natural moment to review your finances. Millions of pounds go unclaimed each year simply because people assume HMRC will handle it automatically. Checking your Personal Tax Account takes a few minutes — and could put hundreds, or even thousands, of pounds back in your pocket.
Disclaimer: This article provides general information only and does not constitute financial or tax advice. If you have a complex tax situation, consult a qualified tax adviser or accountant.
