The objection based on an arbitration agreement (eccezione di compromesso) is procedural in nature, constitutes a matter of simple territorial jurisdiction, and must be raised by the interested party within the time limit provided by Article 166 of the Code of Civil Procedure, upon penalty of forfeiture. It is not cognizable ex officio but is assimilated to an objection of territorial incompetence.
Where the parties accept the objection of incompetence in favour of arbitration, Article 38, paragraph 2, of the Code of Civil Procedure applies, with the consequent striking out of the case from the court roll and recommencement before the arbitrator according to rules corresponding to Article 50 of the Code of Civil Procedure, by virtue of the declaration of constitutional illegitimacy of Article 819-ter of the Code of Civil Procedure pronounced by the Constitutional Court in judgment No. 223/2013.
Acceptance of the objection of incompetence in favour of arbitration entails the nullification of the contested payment order (decreto ingiuntivo) for nullity and the exclusion of the power of the ordinary court to rule on the procedural costs relating to the phase conducted before it, such determination being reserved to the arbitrator to whom the case is remitted.