PEPPOL BIS Billing 3.0 Validator V2

Validate a UBL invoice (Invoice or CreditNote) against EN 16931 and the OpenPEPPOL business rules, without sending a single byte beyond the browser.

Embedded rule set: 45 business rules (BR-*, BR-CO-* calculation, PEPPOL-*, UBL-CR-*), 57 EN 16931 Business Terms, 77 PEPPOL EAS codes, 1 profile. Sources: docs.peppol.eu, PEPPOL Schematron rules and EN 16931-1:2017.

How it works

The validator runs three passes:

1. XML well-formedness: your document is parsed by the browser's native DOMParser. Any mismatched tag or invalid XML character is reported first (E_XML_NOT_WELL_FORMED).
2. UBL root element: the root must be <Invoice> or <CreditNote> in the UBL 2.1 namespace. Otherwise: E_NOT_UBL_ROOT.
3. PEPPOL BIS Billing 3.0 business rules: the BR-NN and PEPPOL-EN16931-RNNN codes listed below are checked against the document structure. Each diagnostic surfaces the EN 16931 Business Term (BT-1, BT-24, etc.) and the XPath of the offending element.

Implemented rules

The V2 validator targets 45 rules from the ~300 in the official PEPPOL-EN16931-UBL.sch Schematron, grouped into four families:

Core EN 16931 — BR-01 → BR-20

• BR-01 — Specification identifier (BT-24) is PEPPOL BIS Billing 3.0.
• BR-02 — Invoice number (BT-1).
• BR-03 — Issue date (BT-2).
• BR-04 — Invoice type code (BT-3) is 380, 381, 384, or 389 (CreditNote: 381, 396).
• BR-05 — Currency code (BT-5) is ISO 4217.
• BR-06, BR-07 — Seller (BT-27) and Buyer (BT-44) name.
• BR-08, BR-09 — Country codes (BT-40, BT-55) ISO 3166-1.
• BR-10, BR-11 — Electronic addresses (BT-34, BT-49) with schemeID from the OASIS code list.
• BR-12, BR-13, BR-14, BR-15 — LegalMonetaryTotal totals (BT-106, BT-112, BT-109, BT-115).
• BR-16 — At least one invoice line (BG-25).
• BR-17, BR-18, BR-19, BR-20 — Payee name and tax representative party fields when present.

Calculation overall — BR-CO-*

Calculation rules check the arithmetic consistency of totals across lines, allowances, charges, and VAT categories. Default tolerance: ±0.011 (cent level) to absorb double-rounding.

• BR-CO-3 — TaxPointDate (BT-7) and InvoicePeriod/DescriptionCode (BT-8) are mutually exclusive.
• BR-CO-9 — VAT category tax amount = base × rate ÷ 100 (BT-117 = BT-116 × BT-119/100).
• BR-CO-10 — BT-106 (sum of lines) = arithmetic sum of BT-131.
• BR-CO-11 — BT-107 (document allowances total) = sum of BT-92.
• BR-CO-12 — BT-108 (document charges total) = sum of BT-99.
• BR-CO-13 — BT-110 (total VAT) = sum of BT-117.
• BR-CO-14 — BT-112 (total with VAT) = BT-109 + BT-110.
• BR-CO-15 — BT-109 (total without VAT) = BT-106 − BT-107 + BT-108.
• BR-CO-16 — BT-115 (amount due) = BT-112 − BT-113 + BT-114.
• BR-CO-17 — BT-116 (VAT category taxable amount) ≥ 0.
• BR-CO-18 — At least one VAT breakdown (BG-23 / cac:TaxTotal/cac:TaxSubtotal).
• BR-CO-19 — If cac:InvoicePeriod (BG-14) is present, BT-73 and/or BT-74 must be filled, with BT-73 ≤ BT-74.
• BR-CO-25 — Payment instructions when BT-115 > 0.

PEPPOL Schematron — PEPPOL-EN16931-R*

• PEPPOL-EN16931-R001 — No empty cbc:* elements.
• PEPPOL-EN16931-R002 — cbc:Note must not be the first child.
• PEPPOL-EN16931-R003 — BuyerReference (BT-10) OR OrderReference (BT-13) required.
• PEPPOL-EN16931-R004 — CustomizationID must be the exact PEPPOL URN.
• PEPPOL-EN16931-R005, R007 — Monetary amounts capped at 2 decimals.
• PEPPOL-EN16931-R006 — cbc:ProfileID (BT-23) required.

PEPPOL UBL Customisation — UBL-CR-* (forbidden elements)

• UBL-CR-001 — cbc:UBLVersionID forbidden (implied by the namespace).
• UBL-CR-002 — cbc:ProfileExecutionID forbidden (covered by cbc:ProfileID).
• UBL-CR-003 — cbc:CopyIndicator forbidden (transport-layer concern).
• UBL-CR-004 — cbc:UUID forbidden (BT-1 is the unique identifier).
• UBL-CR-005 — cbc:IssueTime forbidden (BT-2 is date precision).

Privacy

Limitations

The validator is not — yet — a 1:1 replacement for the official Schematron. Out of scope for this MVP:

• Full VAT rules (BR-AE-*, BR-E-*, BR-IC-*, BR-O-*, BR-S-*, BR-Z-*) that cross-check VAT category, exemption, rate, and country.
• Strict UBL 2.1 XSD validation (child cardinalities, XSD types) — we focus on Business Terms.
• Reference resolution across lines, AllowanceCharge, and TaxTotal.
• Second-tier code-list rules: UnitOfMeasure, UNTDID 4461 PaymentMeansCode, UNTDID 5305 VAT category.
• DocumentReference linking and MIME types (BG-24).

For a production pipeline, running the official PEPPOL-EN16931-UBL.sch Schematron remains the recommended approach.

Related documentation

• PEPPOL — the network overview, four-corner model, and 2026 mandate calendar.
• EN 16931 — the European semantic model for the core elements of an electronic invoice.
• cXML Validator — same approach for Ariba / SAP Business Network documents.