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/883443237
kbo.party/api/v1/enterprise/675395162
kbo.party/api/v1/enterprise/526582712
Lookup establishment by VAT id
kbo.party/api/v1/establishment/2067988926
kbo.party/api/v1/establishment/2017584063
kbo.party/api/v1/establishment/2146741939