# GR-R-006

Source: https://xmlvalid.com/rules/GR-R-006

> Greek Suppliers must provide the VAT number of the buyer, if the buyer is Greek

- Level: error
- Rule sets: Peppol BIS Billing 3.0 rules 3.0.21
- Context: `cac:AccountingCustomerParty[$isGreekSenderandReceiver]/cac:Party`
- Test: `count(cac:PartyTaxScheme[normalize-space(cac:TaxScheme/cbc:ID) = 'VAT']/cbc:CompanyID)=1 and substring(cac:PartyTaxScheme[normalize-space(cac:TaxScheme/cbc:ID) = 'VAT']/cbc:CompanyID,1,2) = 'EL' and u:TinVerification(substring(cac:PartyTaxScheme[normalize-space(cac:TaxScheme/cbc:ID) = 'VAT']/cbc:CompanyID,3))`

Validate a document against these rules: https://xmlvalid.com/validate