/ubl:Invoice/cac:AdditionalDocumentReference

Additional Document Reference Group

Context ID	INV0213
Cardinality	0..n
Usage	M

Description

A reference to an additional document associated with this document.

A group of business terms providing information about additional supporting documents or referenced documents substantiating the claims made in the Invoice.

In Polish KSeF FA(3) invoices it is possible to provide multiple order numbers and their corresponding dates on document level, while the UBL format only allows for one element cac:OrderReference. In order to still be able to accommodate all additional related order numbers the repeatable Additional Document Reference element can be used.

Child elements

Cardinality	Usage	Description	Element
1..1	M	Additional Document Reference ID An identifier for the referenced document.	`cbc:ID`
0..1	-	Additional Document Reference Issue Date The date, assigned by the sender of the referenced document, on which the document was issued.	`cbc:IssueDate`

Details

vrbl-invoice-pl-b2b-3p0

Use the scheme ID schemeID='ON' with the Referenced Document Identifier to indicate an order number.

Example: Providing three order numbers on document level.

<ubl:Invoice>
    <!-- Code omitted for clarity -->
    <!-- First order number -->
    <cac:OrderReference>
        <cbc:ID>000373824</cbc:ID>
        <cbc:IssueDate>2026-01-08</cbc:IssueDate>
    </cac:OrderReference>
    <!-- All additional order numbers -->
    <cac:AdditionalDocumentReference>
        <cbc:ID schemeID="ON">000373854</cbc:ID>
        <cbc:IssueDate>2026-01-08</cbc:IssueDate>
    </cac:AdditionalDocumentReference>
    <cac:AdditionalDocumentReference>
        <cbc:ID schemeID="ON">000373855</cbc:ID>
        <cbc:IssueDate>2026-01-08</cbc:IssueDate>
    </cac:AdditionalDocumentReference>
    <!-- Code omitted for clarity -->
</ubl:Invoice>

Rules

Rule ID	Error Message
VRBL-INV-CORE-85	The Additional Document Reference Group expects a maximum of one Additional Document Reference Document Type.
VRBL-INV-CORE-86	The Additional Document Reference Group expects a maximum of one Additional Document Reference Document Description.