Get advice on National Insurance if you work offshore

Tell HMRC if you're an offshore worker, seafarer or mariner and get advice about your National Insurance contributions.


Apply by post


You should complete the Offshore Worker’s questionnaire if you are a mariner, seafarer or offshore worker.

You’ll need to fill in the form fully before you can print it. You cannot save a partly completed form, so we suggest you gather all your information together before you begin to fill it in.

Applying by post

Send your completed questionnaire with copies of any signed contracts and payslips.

Include the following from your discharge book:

  • pages 2 and 3
  • any pages from the year this questionnaire relates to

Send your documents to the HMRC mariner’s unit:

ISBC, Campaigns and Projects
HM Revenue and Customs

Send your documents even if you do not have your payslips at hand.

If you have any questions about this questionnaire contact the HMRC mariner’s unit.

Email HMRC to ask for this form in Welsh (Cymraeg).

Published 1 January 2014
Last updated 4 June 2020 + show all updates
  1. Mariner's questionnaire has been removed.

  2. Offshore worker's questionnaire has been added.

  3. Postal address for written correspondence to the Marine National Insurance Contributions unit has changed.

  4. First published.