BR-01: Specification identifier (BT-24) is missing

StandardEN 16931-1 (European e-invoicing semantic model)SeverityError: the invoice is rejectedSyntaxUBL, CIIBusiness terms

BT-24 Specification identifier

Applies toEvery EN 16931 invoice: XRechnung, ZUGFeRD 2.x / Factur-X (profiles EN 16931, EXTENDED, XRECHNUNG), Peppol BIS Billing 3.0, and national CIUS such as the Dutch NLCIUS or the Italian/Spanish profiles.

Official rule text

[BR-01] An Invoice shall have a Specification identifier (BT-24).

Why this error occurs

The rule checks that cbc:CustomizationID (UBL) or ram:GuidelineSpecifiedDocumentContextParameter/ram:ID (CII) is present and not blank. The specification identifier tells the receiver which rule set the invoice claims to follow (EN 16931 core, XRechnung, Peppol BIS, Factur-X profile), so validators and receiving systems can apply the right checks. It is usually missing when invoicing software exports a generic UBL or CII file without a profile configured, or when a hand-built template leaves the header out.

How to fix it

In UBL add cbc:CustomizationID as one of the first children of ubl:Invoice or cn:CreditNote (before cbc:ProfileID and cbc:ID). In CII fill rsm:ExchangedDocumentContext/ram:GuidelineSpecifiedDocumentContextParameter/ram:ID. Use the identifier of the specification you target: urn:cen.eu:en16931:2017 for the plain core or Factur-X EN 16931 profile, urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0 for Peppol BIS Billing 3.0, urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0 for XRechnung 3.0. A value consisting only of whitespace counts as empty.

Example (valid)

<cbc:CustomizationID>urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0</cbc:CustomizationID>
<cbc:ProfileID>urn:fdc:peppol.eu:2017:poacc:billing:01:1.0</cbc:ProfileID>

What the validator checks

Checked element (context):

UBL

/ubl:Invoice | /cn:CreditNote

Test (XPath):

normalize-space(cbc:CustomizationID) != ''

CII

/rsm:CrossIndustryInvoice

Test (XPath):

normalize-space(rsm:ExchangedDocumentContext/ram:GuidelineSpecifiedDocumentContextParameter/ram:ID) != ''

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Related rules

BR-02 Invoice number (BT-1) is missing
BR-03 Invoice issue date (BT-2) is missing
BR-04 Invoice type code (BT-3) is missing
BR-05 Invoice currency code (BT-5) is missing
BR-06 Seller name (BT-27) is missing
BR-07 Buyer name (BT-44) is missing
BR-08 Seller postal address is missing
BR-09 Seller country code (BT-40) is missing

Frequently asked questions

What does BR-01 mean?

BR-01 is a en 16931 core rule: An Invoice shall have a Specification identifier (BT-24).

Will my invoice be rejected because of BR-01?

Yes. BR-01 is flagged "fatal"; validators (KoSIT, Peppol access points, the German ZRE/OZG-RE portals) reject the invoice until it is fixed.

Which formats does BR-01 apply to?

Every EN 16931 invoice: XRechnung, ZUGFeRD 2.x / Factur-X (profiles EN 16931, EXTENDED, XRECHNUNG), Peppol BIS Billing 3.0, and national CIUS such as the Dutch NLCIUS or the Italian/Spanish profiles. Syntax: UBL and CII.

Source: EN 16931-1:2017 schematron (CEN TC434, via Peppol BIS 3.0.20). Catalogue generated from the official schematron on 2026-10-14.