PEPPOL-EN16931-R020

The seller electronic address (BT-34) must be provided — the counterpart to BT-49, the address a recipient can reply or send a response message to.

Severity: Error
Applies to: CII, UBL
Rule set: v2026-01-31

Official rule text

Seller electronic address MUST be provided

Why does PEPPOL-EN16931-R020 happen?

The same cause as for the buyer, with an extra reason to skip it: “the recipient knows who the invoice is from”. For automatic processing the sender is an identifier exactly as the recipient is.

How do you fix PEPPOL-EN16931-R020?

Set BT-34 with its scheme attribute under cac:AccountingSupplierParty/cac:Party: cbc:EndpointID with schemeID in UBL, ram:SellerTradeParty/ram:URIUniversalCommunication/ram:URIID in CII. The value is constant for your company.

In the XML

A UBL fragment. The CII path is named above — same change, different element names.

Fails

<cac:AccountingSupplierParty>
  <cac:Party>
    <cac:PartyName>
      <cbc:Name>Muster GmbH</cbc:Name>
    </cac:PartyName>
  </cac:Party>
</cac:AccountingSupplierParty>

Fixed

<cac:AccountingSupplierParty>
  <cac:Party>
    <cbc:EndpointID schemeID="EM">rechnung@muster.de</cbc:EndpointID>
    <cac:PartyName>
      <cbc:Name>Muster GmbH</cbc:Name>
    </cac:PartyName>
  </cac:Party>
</cac:AccountingSupplierParty>

NormAPI provides technical validation, not tax or legal advice.