BR-55: Preceding invoice reference (BT-25) is missing

What does this mean?

Every reference to a preceding invoice (Preceding Invoice reference, BG-3) must contain its invoice number (Preceding Invoice reference, BT-25). The reference exists, the number is missing or empty.

Typical causes

For a credit note or corrective invoice only the date of the original invoice (BT-26) was given.
An empty reference was output.

How to fix the error

Enter the invoice number of the preceding invoice exactly as it appears on that invoice; the issue date (BT-26) can be given in addition.
If there is no preceding invoice, omit the reference entirely.
CII: ram:ApplicableHeaderTradeSettlement/ram:InvoiceReferencedDocument/ram:IssuerAssignedID, UBL: cac:BillingReference/cac:InvoiceDocumentReference/cbc:ID.
Generate and validate the invoice again.

In E-Rechnungsfreund

In the invoice form ("Experte" view), section "Vorausgehende Rechnungen (BG-3)" (preceding invoices), fill in the field "Rechnungsnummer (BT-25)" (invoice number) for every entry or remove the entry.

Example

Wrong

<ram:InvoiceReferencedDocument>
  <ram:FormattedIssueDateTime>
    <qdt:DateTimeString format="102">20260210</qdt:DateTimeString>
  </ram:FormattedIssueDateTime>
</ram:InvoiceReferencedDocument>

Correct

<ram:InvoiceReferencedDocument>
  <ram:IssuerAssignedID>INV-2026-0017</ram:IssuerAssignedID>
  <ram:FormattedIssueDateTime>
    <qdt:DateTimeString format="102">20260210</qdt:DateTimeString>
  </ram:FormattedIssueDateTime>
</ram:InvoiceReferencedDocument>

Related validation rules

• BR-01: Specification identifier (BT-24) is missing
• BR-02: Invoice number (BT-1) is missing
• BR-03: Invoice issue date (BT-2) is missing
• BR-04: Invoice type code (BT-3) is missing
• BR-05: Invoice currency code (BT-5) is missing
• BR-06: Seller name (BT-27) is missing