Use the InvoiceDocumentReference sub-element of the BillingReference element.

Elements

Element	Description
`Invoice/BillingReference/InvoiceDocumentReference/ID`	Specify the preceding invoice's number.
`Invoice/BillingReference/InvoiceDocumentReference/IssueDate`	Specify the date of issue of the previous invoice.

Restrictions

For final invoices and credit notes in Serbia, you must specify the preceding invoice number and issue date.

Example

<ubl:Invoice>
    <!-- Code omitted for clarity -->
    <cac:InvoiceDocumentReference>
        <cbc:ID>9876542541</cbc:ID>
        <cbc:IssueDate>2024-07-01</cbc:IssueDate>
    </cac:InvoiceDocumentReference>
    <!-- Code omitted for clarity -->
</ubl:Invoice>