How must expenditure documents be marked and what applies to the CUP (Italian project partners)?

According to the eligibility rules of the Interreg VI-A Italy-Austria programme, all expenditures must be clearly attributable to the approved project. On invoices and payment confirmations, a clear project reference is to be stated (ITAT project code and/or programme name, project acronym or project title). Electronic documents are equivalent to original documents, provided they comply with the respective national legal requirements.

For Italian project partners, the following applies additionally: If applicable, the CUP (Codice Unico di Progetto) must be stated in accordance with national regulations (Article 11 of Law No. 3 of January 16, 2003 – amended by Decree-Law No. 76 of July 16, 2020, converted into Law No. 120/2020). If the CUP is missing on an electronic invoice (issue date after May 31, 2023), it can be retroactively integrated according to the specifications of the Revenue Agency (Provision of December 10, 2025, Prot. N. 563301/2025) for invoices in connection with public subsidies for economic activities via the web service in the “Fatture e Corrispettivi” portal. After integration, the CUP requirement is considered fulfilled.

If eligible expenditures were incurred before the assignment of the CUP, there is no obligation to state the CUP on the invoice (DL 13/2023); however, in this case, the clear attribution to the project must still be ensured by the accounting documents.