BR-DE-21

The specification identifier (BT-24) should syntactically match the identifier of the XRechnung standard — it tells the recipient the invoice was built to XRechnung, and to which version.

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

Official rule text

Das Element "Specification identifier" (BT-24) soll syntaktisch der Kennung des Standards XRechnung entsprechen.

Why it happens

Commonly only the EN 16931 identifier is present without the XRechnung part, or the version is outdated, or the URN carries a typo.

How to fix it

Send the identifier of the version you produce, for XRechnung 3.0 for example urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0 — as cbc:CustomizationID in UBL, in ram:GuidelineSpecifiedDocumentContextParameter/ram:ID in CII.

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