PARSER CHECKLIST
Core UBL invoice fields
Peppol uses UBL XML with business rules layered on top. A practical importer usually starts by mapping these groups before adding country-specific rules.
Document identifiers
CustomizationID, ProfileID, invoice ID, issue date, invoice type code, currency and a buyer or order reference establish the document context.
Parties
Supplier and customer groups carry legal names, electronic endpoint identifiers, postal addresses, country codes and tax identifiers. Endpoint scheme codes matter as much as the identifier value.
Payment and totals
Payment means identifies how settlement is expected. Tax totals and legal monetary totals must reconcile with every invoice line using the document currency.
Invoice lines
Each line needs an ID, quantity with a unit code, line extension amount, item name, VAT category and a price amount. Preserve decimal values as decimal strings to avoid binary floating-point drift.
National CIUS rules and current Peppol Schematron rules may add constraints beyond the core structure shown here.