- I am an expat
- I am an organisation
If you are a UK employee (under a UK employment contract with a UK employer) and you were posted to Belgium on a work assignment starting on or after 1 January 2021, it is possible to remain covered by UK social security for up to 24 months from the start date of your posting. This is not renewable. The same rule applies if you are posted to Belgium on a work assignment but commute between Belgium and the UK (frontier worker).
If you live in the UK and work in both Belgium and the UK under an employment contract with a UK employer, you can remain covered by only UK social security. Your UK employer should apply for an A1 Certificate (Certificate of Coverage) with HMRC for up to 24 months at a time and renew it thereafter. For more information, please see this UK government page.