Apply for a refund of Class 1 National Insurance contributions
Apply
If onlineyou've been sent a letter from HMRC, apply for a refund of Class 1 National Insurance contributions if you've been invited to do so by HMRC, using form CA4361.
- From:
- HM Revenue & Customs
- Published
- 5 February 2024
- Last updated
- 8 August 2025 — See all updates
Use this form to apply for a refund of Class 1 National Insurance contributions if you’ve been sent a letter from HMRC inviting you to do so.HMRC.
If you would like to submitapply the form by post, you can use the postal form that was sent to you with the letter.
Before you start
You’llYou should only apply for a refund if you have received a letter from HRMC advising you to do so.
You’ll need to sign in with your Government Gateway user ID and passwordpassword. (ifIf you do not have a user ID, you can create one when you first try to sign in).in.
You’ll also need to know the names of any employers you worked for during the tax year that the refund applies to.
Apply for a refund
What happens next
Updates to this page
-
A link has been added to find out when you can expect to receive a reply from HMRC to a query or request you've made.
-
First published.
Sign up for emails or print this page
Update history
2026-08-10 08:53
Guidance updated to explain how to apply for a refund of Class 1 National Insurance contributions and when to apply by post using form CA4361. You can only apply online if your letter includes a claim reference number.
2026-07-21 08:49
A new section – ‘Who can use this form’, has been added to help you choose the correct refund form depending on what’s included in your letter from HMRC.
2025-08-08 12:40
A link has been added to find out when you can expect to receive a reply from HMRC to a query or request you’ve made.
2024-02-05 11:00
First published.