3654915 - Error "[BR-CL-23]-Unit code MUST be coded according to the UN/ECE Recommendation 20 with Rec 21 extension" When Sending Customer Invoice to Peppol

When trying to send a Customer Invoice from Business ByDesign into Peppol, the error "[BR-CL-23]-Unit code MUST be coded according to the UN/ECE Recommendation 20 with Rec 21 extension" occurs.

SAP Business ByDesign

When sending a Customer Invoice from Business ByDesign into Peppol, the following error is present in the Schematron XML:

<error>
    <level>FATAL_ERROR</level>
        <message>[BR-CL-23]-Unit code MUST be coded according to the UN/ECE Recommendation 20 with Rec 21 extension</message>
    <path>ABC</path>
</error>

Where ABC Represents the path in the source XML where the invalid Unit Code was provided.

The PEPPOL specification mandates that unit codes used in invoices must adhere to "UNECE Recommendation 20". This means using the codes defined in the UN/ECE Recommendation 20, with an optional extension using UNECE Recommendation 21. (Specifically, Recommendation 21 codes are used by prefixing them with "X" to avoid conflicts with existing codes in Recommendation 20).

This error message is raised directly from Peppol.

In cases where error "[BR-CL-23]-Unit code MUST be coded according to the UN/ECE Recommendation 20 with Rec 21 extension" is raised, that means that a Unit of Measure was created in Business ByDesign which does not match any of the expected Units of Measure from the Peppol specification.

In order to avoid this issue, only Units of Measure which match the Peppol specification can be used in Invoices sent to Peppol. 

The official Peppol documentation regarding these Unit Codes/Units of Measure can be found in the following link: 

https://docs.peppol.eu/poacc/billing/3.0/2025-Q2/rules/ubl-tc434/BR-CL-23/

In that documentation, all the possible codes for Unit of Measure that Peppol accepts are present. 

A more detailed breakdown of what each code means can be found in this link:

https://docs.peppol.eu/poacc/upgrade-3/codelist/UNECERec20/

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