How to Check If HMRC Owes You a Tax Refund (And How to Claim It)

Millions of UK taxpayers overpay income tax each year without realising it. HMRC estimates billions of pounds in overpaid tax sits unclaimed at any given time. The most common causes: changing jobs, having multiple employers, stopping work mid-year, or being put on the wrong tax code.

Since May 2024, HMRC stopped automatically issuing most refunds. If you've overpaid, you now need to actively claim — HMRC will not send a cheque without you asking. Here's exactly how to check and what to do.

Who Is Most Likely to Have Overpaid?

You may have overpaid tax if you:

• Changed jobs during the tax year (especially if your new employer used an emergency tax code)
• Had multiple jobs or income sources at the same time
• Stopped working before the end of the tax year
• Retired or took early retirement part-way through the year
• Were put on the wrong tax code (e.g. BR — Basic Rate — which taxes all income at 20% with no Personal Allowance)
• Made pension contributions but didn't claim higher-rate relief
• Were a non-taxpayer or low earner who had tax deducted from savings interest

Step 1: Check Your Tax Code

Your tax code tells your employer how much tax-free pay you get. The most common code is 1257L, which gives you the standard Personal Allowance of £12,570.

Wrong codes that commonly cause overpayment:

• BR: taxed at 20% on all earnings with no allowance — often applied to second jobs in error
• 0T: no Personal Allowance at all
• W1 or M1 ("non-cumulative"): tax calculated on a week-by-week or month-by-month basis, ignoring prior earnings

Check your payslip or P60. If your code looks wrong, you can update it directly via your HMRC Personal Tax Account.

Step 2: Check Your Personal Tax Account

Sign in (or register) at gov.uk/personal-tax-account. This is HMRC's online portal and it shows:

• Your income and tax paid year-by-year
• Your current and past tax codes
• Whether a repayment is owed
• Any P800 notices HMRC has issued

If you don't have an account, you'll need a Government Gateway ID — take around 10 minutes to set up with your National Insurance number and a form of ID.

Step 3: Look for a P800 Notice

After each tax year ends (5 April), HMRC reconciles PAYE records and sends a P800 tax calculation to people who appear to have over- or underpaid. Check your online account and your post for this.

If your P800 shows a refund, you must now claim it actively:

• Online via your Personal Tax Account: refund arrives in approximately 5 working days by bank transfer
• By calling HMRC: 0300 200 3300 (have your National Insurance number ready)

Step 4: How Far Back Can You Claim?

You can claim back overpaid Income Tax for up to four tax years from the current date. In June 2026, that means you can claim back to the 2022/23 tax year.

For each year, you'll need your P60 (end-of-year tax summary from your employer) or P45 (leaving certificate from a former employer). If you've lost these, HMRC can often work from their own records.

Step 5: If You're Self-Assessed

If you file a Self Assessment tax return, any overpayment is calculated automatically when you submit. HMRC will:

• Offset it against any tax owed, or
• Refund it — but again, you may need to request the refund via your online account rather than waiting for it automatically

What If You Used a Refund Claims Company?

Many "tax refund companies" advertise online and offer to claim on your behalf. They are legitimate businesses, but they typically charge 25–50% commission on your refund — money that would otherwise come to you in full.

If the process feels complex, use HMRC's own free tools or a free service like the Low Incomes Tax Reform Group (LITRG) before signing anything with a refund company.

Watch Out for Tax Refund Scams

HMRC will never contact you about a refund by text, WhatsApp, or social media, and will never ask you to click a link in an email to claim money. These are always scams. Always go directly to gov.uk/personal-tax-account.

Quick-Action Checklist

• Check your tax code on your payslip or P60 — is it 1257L?
• Sign into gov.uk/personal-tax-account and check for a P800
• Look back up to 4 years (back to 2022/23)
• If a refund is showing, claim it online for fastest payment (~5 working days)
• If you used a refund claims company, check what fee they charged
• Never respond to texts/WhatsApp/social messages claiming to be HMRC

Key Numbers

• Time limit to claim overpaid tax: 4 tax years
• Refund processing time (online claim): ~5 working days
• Standard tax code: 1257L (Personal Allowance of £12,570)
• HMRC phone: 0300 200 3300
• HMRC refunds: no longer automatically issued since May 2024

Sources

• Repayments and Refunds from HMRC — GOV.UK
• Tax Refunds — Low Incomes Tax Reform Group (LITRG)
• PAYE Tax Refunds — LITRG
• Personal Tax Account — GOV.UK
• Tax Codes — GOV.UK
• Phishing and Scam Email Examples — HMRC
• How to Claim a Tax Refund from HMRC — GovExplained

Educational content only — not financial advice. If your tax situation is complex, consider contacting LITRG (free) or a qualified accountant.