Guidance
Apply for a refund of Class 1 National Insurance contributions
If you've been sent a letter from HMRC, apply for a refund of Class 1 National Insurance contributions using form CA4361.
Use this form to apply for a refund of Class 1 National Insurance contributions if you’ve been sent a letter from HMRC.
If you would like to apply by post, you can use the postal form that was sent to you with the letter.
Before you start
You 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 password. If you do not have a user ID, you can create one when you first try to sign in.
You’ll also need to know the names of any employers you worked for during the tax year that the refund applies to.