# UBL 2.1 Invoice

Source: https://xmlvalid.com/schemas/ubl-2.1-invoice

> The Universal Business Language invoice: the syntax behind Peppol BIS Billing 3.0 and one of the two syntaxes of the European e-invoicing standard EN 16931.

UBL 2.1 is the OASIS standard library of business documents; it was published as ISO/IEC 19845. The Invoice document is what Peppol BIS Billing 3.0, XRechnung (UBL flavour) and many national e-invoicing mandates exchange.
The schema checks structure and data types: which elements exist, in what order, and what they may contain.

- Type: XSD
- Version: 2.1
- Namespace: `urn:oasis:names:specification:ubl:schema:xsd:Invoice-2`
- Root element: `Invoice`
- Publisher: OASIS (OASIS copyright notice), source: https://docs.oasis-open.org/ubl/os-UBL-2.1/
- Validate against it: https://xmlvalid.com/validate?schema=ubl-2.1-invoice

## Notes

- This entry checks the schema only. EN 16931, Peppol BIS and XRechnung add business rules (mandatory fields, code lists, calculations) in Schematron; to check those as well, choose the EN 16931, Peppol BIS 3.0 or XRechnung entry.