GR-R-003: For the Greek Suppliers, the VAT must start with 'EL' and must be a valid TIN number

For a Greek supplier (where the supplier country is GR or EL), the VAT identifier in cac:AccountingSupplierParty/cac:Party/cac:PartyTaxScheme/cbc:CompanyID must start with the uppercase prefix EL and the part after that prefix must pass the TIN verification check (u:TinVerification). This is a fatal rule, so an invoice that does not meet this condition fails validation. The test checks substring(.,1,2) = 'EL' and u:TinVerification(substring(.,3)), meaning the first two characters must be exactly EL and the remaining characters must be accepted by the validator's TIN check.

In the UBL invoice, locate the supplier party tax scheme for VAT (where cac:TaxScheme/cbc:ID is VAT) and set cbc:CompanyID to a value beginning with uppercase EL followed by a valid Greek tax identification number (the remainder must pass u:TinVerification). For example, if the TIN is valid, the value should be EL + the TIN. If the supplier country is not GR or EL, this rule does not apply; otherwise correct the CompanyID or the country data as needed.