Tax Code Correction Request Letter Template & Generator

If you need to request HMRC correct an incorrect PAYE tax code, a written letter is the recommended first step — it creates a clear record and shows you're pursuing the matter formally. Below is what a strong tax code correction request should include, plus a free tool to generate yours.

What this letter needs to cover

• State the incorrect code being used and what the correct code should be
• Explain why the code is wrong (previous employment, benefits in kind incorrectly included, etc)
• Request immediate amendment and notify the employer
• Ask for confirmation and calculation of any overpaid or underpaid tax

Why tax codes go wrong more often than you'd expect

Tax codes are frequently based on outdated or incomplete information — a previous job that hasn't been closed off properly, a benefit-in-kind no longer received, or a change in personal allowance that hasn't updated. An incorrect code can mean you're paying too much or too little tax without realising, sometimes for months before it's noticed.

What to include before you send it

• Your current tax code as shown on your payslip, and what you believe it should be
• The reason you believe it's wrong — for example, an old employment still showing, or an incorrect benefit-in-kind
• Any relevant supporting information, such as your P45 or P60 details
• A request for the correction to be made and confirmed in writing

What happens once it's corrected

HMRC will issue a new tax code notice to both you and your employer, and any overpaid or underpaid tax is generally adjusted through your pay going forward, or refunded/collected separately depending on the amount and timing. It's worth checking your next payslip carefully to confirm the correction has actually been applied.

Frequently Asked Questions

How do I check if my tax code is correct?
HMRC's online tax checker service, or your personal tax account, can confirm what your code should be based on your current circumstances.

Can I claim back tax I've overpaid due to a wrong code?
Yes — once corrected, any overpayment can generally be refunded, and HMRC can look back over previous tax years if the error has persisted for some time.

See our full letter template & generator library for related letters, or use our free checkers for guidance specific to your situation.