BR-DE-6Das Element "Seller contact telephone number" (BT-42) muss übermittelt werden.

Official rule text

The seller contact needs a telephone number (BT-42), and it is an error that rejects the invoice rather than a warning. Whether what you put there is a number at all is BR-DE-27, which is only a warning.

Severity
Error
Applies to
CII, UBL
Rule set
v2026-08-31
Checked on

Written and checked against the official KoSIT rule set by Dmytro Yalanskyi, NormAPI.

Why does BR-DE-6 happen?

The phone number appears in the PDF letterhead but is not attached to any contact in the data model — so it is missing when the structured document is generated. BR-DE-6 itself asks only for a non-empty value: "on request" satisfies it. BR-DE-27 is the rule that looks for at least three digits, and it reports as a warning rather than an error.

What the validator checks

The expression the official KoSIT rule set evaluates — not paraphrased, but read from the Schematron file it ships. UBL and CII address different document trees, so the same rule reads differently in each.

UBL
cbc:Telephone[boolean(normalize-space(.))]
CII
ram:TelephoneUniversalCommunication/ram:CompleteNumber[boolean(normalize-space(.))]

Source: rule set v2026-08-31

How do you fix BR-DE-6?

Send the number in BT-42: cac:AccountingSupplierParty/cac:Party/cac:Contact/cbc:Telephone in UBL, ram:SellerTradeParty/ram:DefinedTradeContact/ram:TelephoneUniversalCommunication/ram:CompleteNumber in CII. CII also has DirectTelephoneUniversalCommunication and MobileTelephoneUniversalCommunication — neither counts for BR-DE-6, and EN 16931 warns through CII-SR-234 if they appear at all.

In the XML

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

Fails
<cac:AccountingSupplierParty>
  <cac:Party>
    <cac:Contact>
      <cbc:Name>Buchhaltung</cbc:Name>
      <cbc:ElectronicMail>rechnung@muster.de</cbc:ElectronicMail>
    </cac:Contact>
  </cac:Party>
</cac:AccountingSupplierParty>
Fixed
<cac:AccountingSupplierParty>
  <cac:Party>
    <cac:Contact>
      <cbc:Name>Buchhaltung</cbc:Name>
      <cbc:Telephone>+49 30 1234567</cbc:Telephone>
      <cbc:ElectronicMail>rechnung@muster.de</cbc:ElectronicMail>
    </cac:Contact>
  </cac:Party>
</cac:AccountingSupplierParty>

Related rules

NormAPI provides technical validation, not tax or legal advice.