Message

Dutch VAT numbers MUST have the format (NL123456789B12).

Context
cac:PartyTaxScheme [normalize-space(cac:TaxScheme/cbc:ID) = 'VAT'] /cbc:CompanyID [starts-with(normalize-space(.), 'NL')]
Test
matches(normalize-space(.), '^NL[0-9]{9}B[0-9]{2}$')
Usage
/ ubl:Invoice / cac:AccountingSupplierParty / cac:Party / cbc:EndpointID
/ ubl:Invoice / cac:AccountingSupplierParty / cac:Party / cac:PartyIdentification / cbc:ID
/ ubl:Invoice / cac:AccountingSupplierParty / cac:Party / cac:PartyTaxScheme / cbc:CompanyID
/ ubl:Invoice / cac:AccountingCustomerParty / cac:Party / cbc:EndpointID
/ ubl:Invoice / cac:AccountingCustomerParty / cac:Party / cac:PartyIdentification / cbc:ID
/ ubl:Invoice / cac:AccountingCustomerParty / cac:Party / cac:PartyTaxScheme / cbc:CompanyID
/ ubl:CreditNote / cac:AccountingSupplierParty / cac:Party / cbc:EndpointID
/ ubl:CreditNote / cac:AccountingSupplierParty / cac:Party / cac:PartyIdentification / cbc:ID
/ ubl:CreditNote / cac:AccountingSupplierParty / cac:Party / cac:PartyTaxScheme / cbc:CompanyID
/ ubl:CreditNote / cac:AccountingCustomerParty / cac:Party / cbc:EndpointID
/ ubl:CreditNote / cac:AccountingCustomerParty / cac:Party / cac:PartyIdentification / cbc:ID
/ ubl:CreditNote / cac:AccountingCustomerParty / cac:Party / cac:PartyTaxScheme / cbc:CompanyID