UBL (Universal Business Language) is an open XML standard published by OASIS that defines a library of standard electronic business documents. UBL 2.1 is the version referenced by the EN 16931 European e-invoicing norm and used in PEPPOL.
An UBL invoice (Invoice.xml) contains structured data for all invoice fields — parties, line items, tax totals, payment terms — in a well-defined XML schema validated by XSD and Schematron rules.
Key facts
- Published by OASIS (open standards consortium)
- Current version: UBL 2.1 (ISO/IEC 19845)
- Used in: PEPPOL BIS Billing 3.0, Nordic e-invoicing, EU public procurement
- Alternative to UN/CEFACT CII for EN 16931 compliance