Every eligible person registered in the consular register of a Belgian embassy or consulate can register to vote. This doesn’t happen automatically; for every election you’ll need to confirm how you want to vote: voting personally at a Belgian commune or a diplomatic/consular office, voting by proxy at a Belgian commune or a diplomatic/consular office or voting by mail. The right to vote for Belgians abroad is limited to federal elections.

European elections

If you live in a EU Member State, you can participate in the European elections. After an application at the Belgian embassy or consulate, you will receive a ballot paper in the run-up to the elections. You can cast your vote on the ballot and then send it back in a neutral return envelope to the special electoral office of the Federal Public Service for Home Affairs.

You can also choose to vote for the candidates for European elections in your country of residence.

Contact your embassy or consulate for more information about elections abroad.

Sources:

https://www.vlaanderen.be/nl/vlaams-parlement/verkiezingen/stemrecht-en-stemplicht-bij-verkiezingen/kunnen-belgen-het-buitenland-deelnemen-aan-verkiezingen-belgie

https://diplomatie.belgium.be/nl/Diensten/Diensten_in_het_buitenland/Deelname_aan_verkiezingen/Belgen_binnen_eu