Tell HMRC if you're sending employees to work abroad (CA3821)

Apply to find out if your employee needs to continue paying UK National Insurance contributions while they temporarily work abroad.


Apply online if you're an employer

Apply online if you're an agent

Apply by post


You or your agent should apply online or by post if you’re temporarily sending employees to work in a country:

You must apply by post if your company has been trading in the UK for less than 18 months because you’ll need to send additional evidence with the form.

HMRC may issue your employee a document so they can:

  • continue paying National Insurance contributions to the UK
  • prove that no contributions are due in their temporary place of work

Applying online

To apply online, you need a Government Gateway user ID and password. If you do not have a user ID, you can create one when you apply.

Applying by post

If you’re using an older browser, for example Internet Explorer 8, you’ll need to update it or use a different browser. Find out more about browsers.

You’ll need to fill in the postal form fully before you can print it. You cannot save a partly completed form so you should gather all your information together before you start to fill it in.

Published 4 April 2014
Last updated 20 September 2017 + show all updates
  1. Changes to clarify that you or your agent can use the online form service or postal form to tell HMRC you're sending your employees to work abroad.

  2. Agent apply online (sign in or setup a Government Gateway account) link added to the page.

  3. Welsh translation added to the page.

  4. An online service is now available.

  5. First published.