Use the the online service or the postal form if you're sending employees to work in the European Economic Area (EEA) to find out which member state's social security legislation will apply.
When you’re sending employees to work in the EEA, so that HM Revenue and Customs (HMRC) can determine which member state’s social security legislation will apply you can:
- use the online service (you’ll need to log in to your tax account)
- fill in the form on-screen, print it off and post it to HMRC
If you carry out offshore work on a ship, you’ll need to use the postal version of this form. This is because you’ll need to include a mariner’s discharge book and questionnaire. Fill in the form and send this together with the mariners questionnaire and a copy of yours or the employee’s mariner’s discharge book to Marine National Insurance contributions office at the address shown on the mariner’s questionnaire.
Before you start
The postal form is interactive (one that you fill in on screen) and you must use Adobe Reader to complete it. Downloading Adobe Reader is free. Download the latest version of Adobe Reader.
HMRC are creating new versions of their forms that don’t depend on Adobe Reader. Whilst this work is in progress the following methods can be used to ensure the form will download or open in Adobe Reader:
- whatever browser you are using, review your settings to make Adobe Reader the default program for opening PDF documents
- Windows users should right click on the form link then select ‘Save target as’ or ‘Save link as’
- Mac users should right click on the form link then select “Save linked file as”
- save the form - the recommended place is in the documents folder
- using Adobe Reader you can open the form
If the form still doesn’t open, then contact the Online Services helpdesks for more help.
National Insurance: Working in two or more countries in the EEA (CA8421i)
Use form CA8421i if you normally work in 2 or more countries in the EEA.