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/893908052
kbo.party/api/v1/enterprise/339226816
kbo.party/api/v1/enterprise/400000185
Lookup establishment by VAT id
kbo.party/api/v1/establishment/2182638669
kbo.party/api/v1/establishment/2197865689
kbo.party/api/v1/establishment/2178621384