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Critical

BR-52

Supporting Document Reference Missing (BT-122)

What This Error Means

Each additional supporting document (BG-24) must contain a supporting document reference (BT-122), an identifier for the attached or linked document. In UBL that is cbc:ID in cac:AdditionalDocumentReference, in CII ram:AdditionalReferencedDocument/ram:IssuerAssignedID. The rule applies to every attachment and fires for an empty ID. The rule is fatal.

How to Fix It

Give every cac:AdditionalDocumentReference a non-empty cbc:ID, for example the number of the delivery note or timesheet. A description (BT-123) is optional. BR-DE-22 additionally requires the filename attributes of embedded attachments to differ; the rule compares them character by character.

XML Example
<cac:AdditionalDocumentReference>
  <cbc:ID>LN-2026-06</cbc:ID>
  <cbc:DocumentDescription>Leistungsnachweis Juni 2026</cbc:DocumentDescription>
  <cac:Attachment>
    <!-- Base64 content shortened -->
    <cbc:EmbeddedDocumentBinaryObject mimeCode="application/pdf" filename="Leistungsnachweis-2026-06.pdf">JVBERi0xLjcKJeLjz9MK</cbc:EmbeddedDocumentBinaryObject>
  </cac:Attachment>
</cac:AdditionalDocumentReference>

Fix Automatically

Upload your invoice to our Smart Repair engine. It checks the file against the full KoSIT rule set, including BR-52, and corrects supported fields with a GoBD audit trail.

Open Smart Repair

Related Errors

Other commonly encountered validation errors

SCHEMA-003XSD Schema Violation: Element Missing, Misplaced or Not Allowed (No Rule ID)BR-DE-1Payment Instructions Missing (BG-16)BR-DE-2Seller Contact Missing (BG-6)BR-DE-3Seller City Missing (BT-37)