PEPPOL-EN16931-R003

Explanation

PEPPOL requires either a buyer reference or the buyer's purchase order number. The buyer uses one of the two to match the invoice in its system. German public-sector buyers use their Leitweg-ID (their routing identifier) as the buyer reference.

How to fix

Ask the seller for a corrected invoice that states the buyer's reference or its purchase order number. If the buyer has no reference of its own, an agreed value such as a customer or project number is enough.