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/219640761
kbo.party/api/v1/enterprise/906701461
kbo.party/api/v1/enterprise/460165624
Lookup establishment by VAT id
kbo.party/api/v1/establishment/2259918272
kbo.party/api/v1/establishment/2254431735
kbo.party/api/v1/establishment/2229613096