BR-55

Every preceding invoice reference (BG-3) must contain the preceding invoice's number (BT-25). Without it the group refers to nothing in particular.

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

Official rule text

Each Preceding Invoice reference (BG-3) shall contain a Preceding Invoice reference (BT-25).

Why does BR-55 happen?

The group is created to carry the original invoice's date, or comes out of a correction template empty. The number sits in a different field from the one expected.

How do you fix BR-55?

Set BT-25 in cac:BillingReference/cac:InvoiceDocumentReference/cbc:ID in UBL, ram:InvoiceReferencedDocument/ram:IssuerAssignedID in CII. When the reference is required at all is covered by BR-DE-26.

In the XML

A UBL fragment. The CII path is named above — same change, different element names.

Fails

<cac:BillingReference>
  <cac:InvoiceDocumentReference>
    <cbc:IssueDate>2026-07-15</cbc:IssueDate>
  </cac:InvoiceDocumentReference>
</cac:BillingReference>

Fixed

<cac:BillingReference>
  <cac:InvoiceDocumentReference>
    <cbc:ID>RE-2026-0041</cbc:ID>
    <cbc:IssueDate>2026-07-15</cbc:IssueDate>
  </cac:InvoiceDocumentReference>
</cac:BillingReference>

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