UBL Invoice Validator

Universal Business Language (UBL) 2.1 is an OASIS open standard that defines XML document formats for business documents like invoices, credit notes, and orders. It is the syntax used by Peppol BIS Billing 3.0 and the EN16931 European e-invoicing standard.

UBL 2.1 defines the XML structure: the tags, elements, and data types. Peppol BIS Billing 3.0 is a business profile on top of UBL that adds constraints, including which fields are mandatory, which code lists to use, and what business rules must be satisfied. EN16931 sits between them as the European semantic model. When you validate here, we check all three layers.

This validator supports UBL 2.1 Invoice (InvoiceTypeCode 380 and variants like 384, 386, 389) and UBL 2.1 CreditNote (InvoiceTypeCode 381). These are the document types defined in Peppol BIS Billing 3.0.

Validation runs two sets of schematron rules: EN16931 (CEN) business rules that check European standard compliance (BR-series rules), and Peppol BIS rules that check network-specific requirements like electronic address scheme IDs, process identifiers, and code list values.

SEF (Stylesheet Export File) is a compiled form of XSLT stylesheets used by SaxonJS. The Peppol schematron rules (.sch files) are compiled into SEF format so they can run efficiently in the browser or on Cloudflare Workers without a full XSLT processor.

No. UBL 2.1 added significant elements compared to 2.0, including better support for credit notes, self-billing, and additional code lists. Peppol BIS Billing 3.0 specifically requires UBL 2.1. Documents using UBL 2.0 namespaces will fail validation.