KBO.party offers the monthly KBO csv export as a REST service.
Free in beta
Lookup company by VAT id
kbo.party/api/v1/enterprise/222030426
kbo.party/api/v1/enterprise/648887339
kbo.party/api/v1/enterprise/782393981
Lookup establishment by VAT id
kbo.party/api/v1/establishment/2252292290
kbo.party/api/v1/establishment/2160965505
kbo.party/api/v1/establishment/2047951397