How to Claim a Tax Refund Online in 2026 — Step by Step

HMRC paid out over £2.5 billion in income tax refunds last year. A significant chunk of that went unclaimed because people didn't know how to apply or thought the process was complicated. It isn't. Here is the complete step-by-step guide for 2026.

Route 1: Through Your P800

After each tax year ends on 5 April, HMRC reviews millions of PAYE records and issues P800 tax calculation notices to anyone who appears to have overpaid or underpaid. If you receive a P800 showing an overpayment:

1. Check the amounts match your expectations
2. If the P800 includes an online claim link, use it — the refund arrives in 5 working days
3. If no link, HMRC will send a cheque automatically within 45 days — no action needed

Route 2: Personal Tax Account (Proactive Claim)

1. Go to gov.uk/personal-tax-account and sign in with your Government Gateway account
2. Select "Check your Income Tax" from the menu
3. Review the tax calculation for the relevant year(s)
4. If an overpayment is shown, click "Claim a tax refund" and enter your bank details
5. Refund arrives within 5 working days

Route 3: Self Assessment (If You File a Return)

If you complete an annual Self Assessment return, any overpayment is automatically calculated. You choose whether to receive a repayment to your bank account or offset it against the next year's tax bill.

Route 4: By Post (If None of the Above Work)

Write to HMRC at: Pay As You Earn, HM Revenue and Customs, BX9 1AS. Include your full name, NI number, date of birth, and details of the overpayment you believe occurred.

How Far Back Can You Claim?

You can reclaim overpaid tax for the last 4 tax years. In the 2026/27 tax year, that means you can claim for 2022/23, 2023/24, 2024/25, and 2025/26. Claims for older years are generally time-barred.

Frequently Asked Questions

Do I need an accountant to claim a tax refund?

No. HMRC's online system is free and straightforward for most PAYE workers. Tax refund companies that advertise heavily typically charge 30–48% of your refund as their fee. Unless your affairs are complex, there's no need to use them.

How long does the refund actually take?

Online claims via Personal Tax Account or a P800 link: 5 working days. Cheque via post: up to 45 working days. Self Assessment refunds: 5–10 working days after the return is processed.

Check whether you're overpaying tax with our Overpaying Tax Calculator.