Error code PEPPOL-EN16931-R003
Buyer reference or order reference is missing
Peppol invoices need either a buyer reference (BT-10) or a purchase order reference (BT-13).
The official rule
“A buyer reference or purchase order reference MUST be provided.”
Official text, in the language the rule set publishes it in.
Common causes
- The customer gave no reference or order number, and none was entered.
- The reference is filled in but in a field that isn't exported.
How to fix it
- Ask the customer for their reference or purchase order number and fill it in.
Where to fix it in your software
- Billit:
Factureer je aan een overheidsinstantie, bijvoorbeeld via het Mercurius-platform? Vul dan het PO-nummer in.
(help page)
From each provider's own help page, read on 25 October 2026. Menus can change; we are not linked to these providers.
Wrong vs. right (UBL)
Wrong
<cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode> <cac:AccountingSupplierParty>
Right
<cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode> <cbc:BuyerReference>PO-2026-17</cbc:BuyerReference> <cac:AccountingSupplierParty>