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E-invoice error explained

BR-DE-21: Specification identifier does not match XRechnung

BT-24 states which standard the file follows.

What the rule checks

BT-24 states which standard the file follows. For XRechnung 3.0.x the value is urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0, for the XRechnung extension urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0#conformant#urn:xeinkauf.de:kosit:extension:xrechnung_3.0. Many validators pick their rule set from this value, so a wrong value often means the file is not recognised as XRechnung at all.

Official rule text

The element "Specification identifier" (BT-24) should syntactically match the identifier of the XRechnung standard.

Source: KoSIT configuration XRechnung 3.0.2 (31 Jan 2026).

Typical causes

  • The identifier of an older version is still there, for example xrechnung_2.3.
  • The patch version was added, for example xrechnung_3.0.2. The identifier only carries major and minor version.
  • The ZUGFeRD profile identifier urn:cen.eu:en16931:2017 is used without the XRechnung part.
  • A typo or leading or trailing spaces.

How to fix it

Set rsm:ExchangedDocumentContext/ram:GuidelineSpecifiedDocumentContextParameter/ram:ID in CII, or cbc:CustomizationID in UBL, to the exact XRechnung 3.0 value.

Example

Wrong (CII)

<rsm:ExchangedDocumentContext>
  <ram:GuidelineSpecifiedDocumentContextParameter>
    <ram:ID>urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_2.3</ram:ID>
  </ram:GuidelineSpecifiedDocumentContextParameter>
</rsm:ExchangedDocumentContext>

Right (CII)

<rsm:ExchangedDocumentContext>
  <ram:GuidelineSpecifiedDocumentContextParameter>
    <ram:ID>urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0</ram:ID>
  </ram:GuidelineSpecifiedDocumentContextParameter>
</rsm:ExchangedDocumentContext>

Wrong (UBL)

<cbc:CustomizationID>urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0.2</cbc:CustomizationID>

Right (UBL)

<cbc:CustomizationID>urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0</cbc:CustomizationID>

In Dynamics 365, Business Central and Finance

Sales / Project Operations: Sales and Project Operations have no e-invoice output out of the box. In the WBS Invoice Accelerator for Dynamics 365 the Accelerator sets BT-24 itself for each format.

Business Central: The value comes from the XRechnung format of the e-document service. Keep Business Central up to date.

Finance: For xRechnung version 3 and later, the ER format configurations Sales Invoice DE and Project Invoice DE must be imported in the version Microsoft names or later.

Related error codes

All error codes

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