This is reported in La Libre Belgique on the basis of a response of the Minister for Finance, Johan Van Overtveldt (New Flemish Alliance), specifically addressed to the federal deputy Gautier Calomne (MR).
Mr Calomne requested from the minister the “gender and language” of the returns, in communes with specific language facilities and in Brussels. In these regions, citizens should reveal their language preference when submitting their annual tax return with their given tax authority. It emerges that 92% of inhabitants receive their income tax return (known as an “IPP” in French-speaking Belgium) actually in French.
These data are not as precise as a specific language census. All the same, La Libre Belgique observes that information taken from IPP returns gives a good indication of the actual numbers of people speaking French. The daily newspaper mentions that actual censuses have not been possible since the linguistic border was fixed in 1962.
The Brussels Times
Tax returns indicate that 92% of Brussels is French-speakingMonday, 04 December 2017 16:19
Language data from 2017 tax returns, indicate that 92% of Brussels is French-speaking.