Brexit residency rules for UK citizens moving to Brussels

The short version

If you already lived in Belgium before 1 January 2021, you're likely protected under the UK-EU Withdrawal Agreement and should hold (or be transitioning to) an "M card" as a beneficiary of that agreement. If you're moving to Brussels now, for the first time, none of that applies to you — you're treated as a third-country national, the same as someone moving from the US, Canada or Australia (Belgian Immigration Office).

Visiting vs relocating

For short trips, UK passport holders can still enter Belgium and the rest of the Schengen area visa-free for up to 90 days in any rolling 180-day period. That's fine for house-hunting trips or a first look around, but it is not a route to actually living in Belgium (UK government guidance).

If you intend to stay longer than 90 days — which covers most genuine relocations — you need to sort out the right authorisation before or shortly after arrival, and then register your residence formally. Skipping this step is the single most common thing that delays a move.

What "third-country national" means in practice

It means your residence application is assessed on its own merits rather than under EU free-movement rules. Depending on your circumstances (employment, self-employment, family reunification, sufficient means, retirement, etc.), you'll need to apply for the category of permit that matches your situation, in some cases before you travel. The Belgian Immigration Office (DOFI) is the authority that sets out the category-specific requirements (DOFI — UK nationals).

If you moved before the end of 2020

UK nationals (and their family members) who were already living in Belgium before 31 December 2020 fall under the Withdrawal Agreement. They were required to apply for the new "M card" (or "N card" for frontier workers) at their commune, and older residence documents (E, E+, F, F+ cards, Annex 8/8bis/15) stopped being valid on their own after 31 March 2022. If this describes you or a family member and the paperwork was never finalised, it's worth sorting out — the deadlines have passed but the underlying protection still needs the right documentation in place.

Registering once you arrive

Regardless of which category applies, once you're settled at an address you'll need to register at your local commune within eight working days of arrival — this starts your residence file and, eventually, your National Register Number. See our step-by-step commune registration guide for exactly what that looks like.

Getting this wrong is expensive to fix

Because the rules genuinely changed after Brexit, a lot of the "how my colleague did it in 2018" advice circulating among expats no longer applies. Getting professional immigration advice for your specific category — before you commit to a move date — avoids the situation where you arrive and then discover you needed a different visa type.

Sources: Belgian Immigration Office (DOFI), DOFI — UK nationals, UK Government — Living in Belgium