Search Q&A
Do agreements in English have legal value in the Brussels region?
According to my notaire it has to be in one of the official languages - so not in English.
The only (recent) exception is that employment contracts in English are valid as a result of a judgement by the European Court, but that ruling depended on EU employment issues which wouldn't extend into other areas.
English (or any other language) is fine, but if it needs to be enforced, you will need to have it "officially" translated to FR or NL.