Guidance

Apply for a refund of National Insurance contributions

If you've been sent a letter from HMRC, apply for a refund of National Insurance contributions paid in error by your employer.

Use this form to apply for a refund of National Insurance contributions if HMRC has sent you a letter.

Once you’ve applied, we’ll confirm you’re due a refund and write to you with the outcome.

Who can use this service

You can apply if HMRC has written to you about National Insurance contributions paid in error by your employer.

You can only apply if you have received a letter from HMRC telling you that you may be due a refund.

If you’re a personal representative or an employer, you cannot use this service. If you’re a personal representative you must follow the instructions in your own letter.

Before you start

You’ll need:

  • your claim reference number (shown on your letter)
  • bank or building society account details

If you’ve received more than one National Insurance refund letter, you’ll need to make a separate claim for each one.

If you do not have a claim reference number on your letter

If there’s no claim reference number on your letter, you cannot use this service. You’ll need to check how to claim your National Insurance refund.

Apply online

You’ll need to sign in to use this service. If you do not already have sign in details, you’ll be able to create them.

Start now

If you cannot apply online

You can apply using the form on the back of your letter and send it to the address shown at the top of the letter.

What happens next

HMRC will check your application and write to you with the outcome.

If you want to see how long it will take to hear back from us you can check when you can expect a reply from HMRC.

Updates to this page

Published 31 March 2026

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