The buyer's purchase order number. Many buyers auto-match incoming invoices against their orders — without this reference the matching fails.
cac:OrderReference/cbc:IDrsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ram:BuyerOrderReferencedDocument/ram:IssuerAssignedIDThe Billhorse validator checks XRechnung, ZUGFeRD and Factur-X right in your browser — your file is never uploaded.
Open the validator ← All EN 16931 terms
Semantics: EN 16931-1. Simplified explanation in our own words — the norm is authoritative.