PEPPOL-EN16931-R003
A buyer reference or purchase order reference MUST be provided.
What does this rule mean?
Neither a buyer reference (BT-10) nor a purchase order reference (BT-13) is given.
The receiver needs at least one hook to route the invoice internally — with neither, it stalls in the inbox.
Official rule message (standard)
A buyer reference or purchase order reference MUST be provided.
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 | ubl-invoice:Invoice
CII
ram:ApplicableHeaderTradeAgreement
Technical test
The rule passes when this Schematron expression holds true:
ram:BuyerReference or ram:BuyerOrderReferencedDocument/ram:IssuerAssignedIDHow to fix it
A missing or incorrect business entry only you can supply. Add or correct it, then re-check.
Add the buyer reference or the purchase order number.
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.