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/872215882
kbo.party/api/v1/enterprise/883769671
kbo.party/api/v1/enterprise/804000435
Lookup establishment by VAT id
kbo.party/api/v1/establishment/2055286874
kbo.party/api/v1/establishment/2206167307
kbo.party/api/v1/establishment/2076605989