How to Claim a Tax Refund UK

Millions of UK taxpayers overpay income tax every year, yet many never claim the refund they are owed. HMRC repaid over £4.1 billion in overpaid income tax in 2022/23 alone — and estimates suggest a further significant sum goes unclaimed each year. Whether you overpaid due to an incorrect tax code, emergency tax on a new job, unused personal allowance, or allowable work expenses, this guide walks you through exactly how to claim your money back from HMRC in 2025.

Who Can Claim a Tax Refund?

You may be entitled to a UK income tax refund if you are or have been a UK taxpayer who paid too much income tax through PAYE (Pay As You Earn) or through Self Assessment. The most common situations where a refund is due include:

Common Reasons for Overpaying Tax in Detail

1. Incorrect or Emergency Tax Code

Your tax code tells your employer how much income tax to deduct. The standard code for 2025/26 is 1257L, which gives you the full personal allowance of £12,570. Problems arise when:

• You start a new job without a P45 and are placed on an emergency tax code (such as 1257L W1/M1 or the prefix 0T)
• HMRC issues the wrong code due to outdated information
• You have multiple jobs and the personal allowance is allocated incorrectly
• A benefit in kind (such as a company car) changes your code without your knowledge

Emergency tax codes W1 (week 1) or M1 (month 1) treat each pay period as if it were your first, meaning none of your previous tax-free pay is taken into account. If you spent several months on an emergency code, you have almost certainly overpaid.

2. Working Part of the Tax Year

The UK tax year runs from 6 April to 5 April. If you only work part of the year — perhaps starting a new job in January or finishing work in September — your employer calculates your tax assuming you will earn the same each month for the full year. If you earned less than the annual personal allowance over the year, you will have overpaid.

3. Higher Rate Tax on Pension Contributions

Many higher rate (40%) taxpayers whose employers operate relief-at-source pension schemes only receive basic rate (20%) tax relief automatically. The additional 20% must be claimed through Self Assessment or directly from HMRC. HMRC estimates that tens of thousands of higher rate taxpayers miss out on this relief each year.

Understanding Your P800 Notice

After the end of each tax year (5 April), HMRC reviews PAYE records and sends a P800 Tax Calculation to anyone who appears to have overpaid or underpaid tax. P800 letters are typically sent between June and October.

What Your P800 Shows

What to Do If Your P800 Is Wrong

P800 calculations are based on the information HMRC holds. If you believe the figures are incorrect — for example, your income is wrong or expenses have not been included — do not ignore it. Contact HMRC to provide the correct information. Getting it wrong in your favour is still an underpayment that HMRC will chase.

Checking Your Personal Tax Account

Even if you do not receive a P800, you can check whether you are owed a tax refund by logging into your HMRC Personal Tax Account at gov.uk/personal-tax-account. You will need a Government Gateway user ID and password.

Your Personal Tax Account shows:

• Your current and previous tax codes
• Your income tax calculation for the current and previous tax years
• Any refunds or underpayments
• Your National Insurance record
• PAYE income reported by your employer(s)

How to Claim a Tax Refund Online (Step by Step)

Claiming online is the fastest and simplest method. HMRC aims to process online claims within 5 working days.

1. Go to gov.uk/personal-tax-account Sign in with your Government Gateway user ID and password. If you do not have one, you can create one — you will need your National Insurance number and a form of ID (passport, driving licence, or a recent payslip).
2. Check your tax calculation Navigate to "Check your Income Tax" or look for any P800 notification. This will show whether HMRC believes you have overpaid or underpaid tax.
3. Confirm your bank details To receive a direct bank transfer, you will need to provide your UK bank account sort code and account number. This is the fastest payment method.
4. Submit your claim Follow the on-screen instructions to claim your refund. You may also need to confirm your address if a cheque is being sent.
5. Wait for payment Online claims paid by bank transfer typically arrive within 5 working days. Cheques take longer (usually 2-3 weeks from despatch).

How to Claim a Tax Refund by Post

If you cannot claim online or prefer to claim by post, HMRC accepts postal claims. This is slower — typically 6-8 weeks — but fully valid. Which form you use depends on your situation:

Claiming Through Your Employer (In-Year)

If you are currently employed and have an incorrect tax code, you do not have to wait until the end of the tax year to get a refund. You can:

• Contact HMRC to have your tax code corrected. Your employer will then adjust your tax deductions in the next payroll, and any overpayment from earlier in the year will be refunded through your pay.
• Check your payslip to see your current tax code and compare it to what you expect. If it looks wrong, contact HMRC on 0300 200 3300.

HMRC can issue a new tax code to your employer within a few days of being contacted, making this the fastest way to recover overpaid tax in the current year.

Work Expenses and Uniform Allowance

Many employees are entitled to tax relief on work expenses that they paid for themselves and that were necessary for their job. HMRC does not automatically give this relief — you must claim it.

What You Can Claim

Uniform Allowance: Flat Rate by Profession

HMRC has agreed flat-rate deductions for certain professions. You do not need receipts to claim these amounts:

Tax Years and the 4-Year Time Limit

The UK tax year runs from 6 April to 5 April the following year. Tax refund claims are time-limited:

Average Tax Refund Amounts

How much can you expect to receive? The amount varies enormously depending on the reason for overpayment. Here are some typical scenarios:

According to HMRC data, the average income tax refund paid to individuals is around £900, though this figure is heavily influenced by higher-value claims. The most common refunds for routine PAYE overpayments tend to be in the £100-£500 range.

Tax Refund Companies: What You Need to Know

There are many private companies that will offer to claim your tax refund for you — typically charging 25-50% of whatever they recover. While these companies are legal, there are significant reasons to claim directly through HMRC instead:

Claiming Directly vs Using a Refund Company

Frequently Asked Questions