VAT-liable individuals must submit their 2024 customer listing by March 31, 2025, primarily through Intervat. Paper submissions are only allowed for those authorized for paper VAT returns. Specific procedures exist for those ceasing activities, joining/leaving VAT units, or having no reportable transactions, including ticking a box in the final periodic VAT return or submitting a nil listing for certain schemes. Different rules apply to agricultural, exemption schemes, and members of VAT units.
Source: financien.belgium.be
Note that this post was (partially) written with the help of AI. It is always useful to review the original source material, and where needed to obtain (local) advice from a specialist.