Peppol BIS Billing 3.0 · rule
UBL-CR-137
What does UBL-CR-137 mean? A UBL invoice should not include the Signature
Why did my invoice fail UBL-CR-137?
The invoice should not contain the element cac:Signature, i.e. a UBL Signature block. This is one of the EN 16931 "cardinality restriction" (UBL-CR) warnings: the UBL 2.1 schema allows the element, but it maps to no business term in the EN 16931 core invoice model, so a compliant core invoice must leave it out. EN 16931 deliberately keeps digital signatures outside the invoice document itself; there is no business term for an embedded signature, so signing is handled at the transport or envelope level instead. Receivers may ignore or reject data carried in such elements, so remove it or move the information to the supported business term.
Official rule text
A UBL invoice should not include the Signature
Common causes
- A signing library embeds an XML-DSig cac:Signature block directly into the invoice document
- A template from a national or legacy UBL profile that required embedded signatures was reused
- The sender confuses document-level signing (not modelled by EN 16931) with transport-level security, which is where signing belongs
Related rules
UBL-CR-001 · UBL-CR-002 · UBL-CR-003 · UBL-CR-004 · UBL-CR-005 · UBL-CR-006 · UBL-CR-007 · UBL-CR-008
Paste it into the live demo, or call POST /v1/validate. See the quickstart.