PEPPOL-EN16931-R080
Only one project reference is allowed on document level
What does this rule mean?
More than one project reference is given at document level.
Peppol allows exactly one project reference per document.
Official rule message (standard)
Only one project reference is allowed on document level
Where the rule applies
Syntax: CII · UBL
The same rule, expressed twice: UBL and CII name the same fields with different paths. Running a CII file against the UBL rules is why you get errors that mean nothing.
UBL
ubl-creditnote:CreditNote
CII
ram:ApplicableHeaderTradeAgreement
Technical test
The rule passes when this Schematron expression holds true:
count(ram:AdditionalReferencedDocument[ram:TypeCode='50']) <=1How to fix it
A missing or incorrect business entry only you can supply. Add or correct it, then re-check.
Reduce to a single project reference.
Correct the affected entry in your XML, then re-check the invoice. Validation runs locally in your browser — your file never leaves your machine.
Check an e-invoice here
Drop an XML or ZUGFeRD PDF file here. Validation runs locally in your browser against EN 16931 — your file never leaves your machine.