Legal Basis and Regulatory Applications of the Once-Only Principle: The Italian Case

This study presents how the OOP is related to the constitutional and institutional principles concerning the good performance and impartiality of public authorities and the protection of citizens’ rights against the action of public administration, with special regard to the Italian regulatory framework. The national path towards the implementation of the principle is examined, starting from the obligation of the use of self-certifications in place of certificates and the automatic acquisition of data and documents in administrative procedures down to the digitalization of administrations and the interoperability of public databases. A specific paragraph is devoted to the OOP in public procurement, as crucial for development of the European digital single market.