Peppol BIS Billing 3.0 · rule

UBL-CR-020

Layer en16931·Checked against Peppol BIS Billing 3.0 2026.5

What does UBL-CR-020 mean? A UBL invoice should not include the OrderReference CustomerReference

Why did my invoice fail UBL-CR-020?

The UBL 2.1 schema allows a CustomerReference child inside cac:OrderReference, but this element is not part of the EN 16931 core invoice model, so a compliant invoice should not include it. UBL-CR rules exist because EN 16931 uses only a subset of full UBL: any element outside that subset carries data the receiver is not required to process. In the core model, cac:OrderReference conveys the purchase order reference (BT-13) and should be limited to cbc:ID (the purchase order reference, BT-13); Peppol additionally uses cbc:SalesOrderID for BT-14.

Official rule text

A UBL invoice should not include the OrderReference CustomerReference

Common causes

Your ERP or invoicing software exports the full UBL 2.1 OrderReference structure, including CustomerReference, instead of the EN 16931 subset
A generic UBL template or mapping copies every available source field into the XML rather than only the core-model elements
Data intended for another business term was mapped into cac:OrderReference/CustomerReference because no obvious core element existed for it

How do I fix it?

<cac:OrderReference>
  <cbc:ID>PO-2024-0815</cbc:ID>
</cac:OrderReference>

Check your invoice against this rule

Paste it into the live demo, or call POST /v1/validate. See the quickstart.