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/714325024
kbo.party/api/v1/enterprise/280300108
kbo.party/api/v1/enterprise/602354063
Lookup establishment by VAT id
kbo.party/api/v1/establishment/2067645763
kbo.party/api/v1/establishment/2203855440
kbo.party/api/v1/establishment/2027969201