1. Introduction
During 2026, with regard to the actions brought by GSE to recover incentives unduly paid following forfeiture measures (provvedimenti decadenziali) that have become unchallengeable, there has been a revision of the allocation of jurisdiction between the administrative courts and the ordinary courts.
A central role in this shift is attributable to Order No. 5925 of 16 March 2026 (subsequently confirmed by a number of later decisions, including Nos. 5926, 5927, 9087, 9097, 14327 and 21796 of 2026), in which the Joint Divisions of the Court of Cassation (Sezioni Unite) clarified the following principle of law: where the forfeiture (or a measure having equivalent effect) has by now become final, the claim for restitution brought by GSE falls within the jurisdiction of the ordinary courts and not of the administrative courts. The Council of State has most recently aligned itself with this approach in Judgment No. 7582 of 16 October 2026.
The Regional Administrative Court for Lazio (TAR Lazio), Section III ter, has instead taken a different path: by Order No. 14647 of 7 September 2026, it raised a question of constitutional legitimacy concerning Article 133, paragraph 1, letter o), of the Code of Administrative Procedure (c.p.a.), as currently interpreted by the Court of Cassation.
2. The Previous Approach
For a long time, the administrative case law, with the endorsement of the Court of Cassation itself, interpreted Article 133, paragraph 1, letter o), c.p.a. broadly. Under this reading, the exclusive jurisdiction of the administrative courts covered not only disputes concerning the grant, refusal or revision of incentives, but also disputes concerning their subsequent restitution.
The underlying rationale was that GSE’s claim for restitution was closely linked to the exercise of public authority, owing to the connection between the incentives and the function of directing national energy production.
The request for restitution was therefore regarded as a “consequential and bound measure” (provvedimento consequenziale e vincolato), possessing an autonomous administrative character of its own, to the point that GSE could bring proceedings by way of an application for a payment order (ricorso per ingiunzione) under Article 118 c.p.a. before the TAR.
A recent example of this approach is the judgment of TAR Lazio, Section III ter, No. 14021 of 16 July 2025, based on the “double protection” (doppia protezione) afforded by Articles 133, paragraph 1, letter o), and 118 c.p.a. (on this point, reference is made to the dedicated commentary available at the followinglink).
In essence, the administrative courts founded their jurisdiction on the public-law origin of the relationship, rather than on the actual subject matter of the claim brought.
3. The Change in Approach of the Joint Divisions of the Court of Cassation
The change in direction is based on the criterion of the substantive petitum. What matters is not so much the relief sought, but rather the causa petendi: the true nature of the position asserted in the proceedings, as it emerges from the claimant’s pleadings, not from the objections raised by the counterparty, unless those objections reveal that the claim inherently requires, from the outset, the determination of matters falling outside the jurisdiction of the court seised.
On this basis, the Joint Divisions, in the decisions referred to above, clarified that Article 133, paragraph 1, letter o), c.p.a. “does not entail a generalised allocation of all disputes originating in incentive relationships or in prior administrative measures”. For the exclusive jurisdiction to apply, the court must be called upon to assess, even if only indirectly, a measure or procedure that expresses the public function of directing energy production: areas in which GSE acts in a position of supremacy, even where the relationship is governed by agreements (convenzioni).
The decisive factor is said to be the “finality” of the forfeiture: if the measure has not been challenged or has been upheld by a judgment that has become res judicata, GSE’s power is considered to be by then exhausted. The forfeiture thus becomes an “irretractable factual and legal precondition” (presupposto fattuale e giuridico irretrattabile), which can no longer be called into question.
Consequently, the claim for restitution does not require any new exercise of public authority: the court merely takes note of the forfeiture, in a purely declaratory manner, and verifies whether the title justifying the payments has ceased to exist and whether an obligation of restitution arises under Article 2033 of the Italian Civil Code.
It is, therefore, an ordinary action for the protection of a right of credit, cognisance of which — in the view of the Joint Divisions — falls to the ordinary courts. This is consistent with the principle whereby a dispute whose cause of action is an objective undue payment (indebito oggettivo) arising from administrative proceedings that have already determined the relationship falls within the jurisdiction of the ordinary courts (Court of Cassation, Joint Divisions, Judgment No. 10016 of 15 April 2021).
4. Application of the Principle by the Council of State
In its recent Judgment No. 7582/2026, the Council of State applied these principles to a recovery case brought by way of summary injunction proceedings (procedimento monitorio) before the administrative courts.
GSE had declared the forfeiture at the conclusion of a verification process in which it had not been possible to carry out an on-site inspection and in which requests for supplementary documentation had gone unanswered; neither the forfeiture nor the subsequent request for restitution had been challenged.
Having obtained a payment order (decreto ingiuntivo) from TAR Lazio, GSE saw the opposition brought by the party subject to the order dismissed: the court of first instance had held that it had exclusive jurisdiction and had declared inadmissible the objections concerning the forfeiture, which had by then become final.
The Council of State instead found that GSE’s application for a payment order was exclusively restitutory in nature: its sole purpose was to obtain a title for enforced recovery. The letter by which GSE had responded to the requests for clarification merely sought payment of a sum already due, without exercising any new authoritative power.
For the purposes of allocating jurisdiction, according to the administrative courts, a mere causal link with the prior power of verification is not sufficient: Article 133, paragraph 1, letter o), c.p.a. requires that the subject matter of the dispute be the exercise, even if only indirect, of an authoritative power, which in this case had by then been definitively exhausted.
On this basis, the court declared a lack of jurisdiction, set aside the first-instance judgment and revoked the payment order.
This outcome had already been anticipated by the Council of State’s Judgment No. 6267 of 3 August 2026, which had characterised GSE’s reminder letter as a “mere reminder of payment, an expression of the Manager’s claim as creditor, not a constitutive act” of the obligation, clarifying that the identification of the debtor liable for restitution cannot be made to depend on an authoritative decision taken by the creditor itself.
5. Order No. 14647/2026 of TAR Lazio and the Referral to the Constitutional Court
Almost in parallel with the consolidation of the approach taken by the Joint Divisions, TAR Lazio, Section III ter, by Order No. 14647 of 7 September 2026, raised a question of constitutional legitimacy concerning Article 133, paragraph 1, letter o), c.p.a., as interpreted by the Court of Cassation.
According to the TAR, the provision should bring within the exclusive jurisdiction of the administrative courts also restitutory disputes, or in any event disputes concerning consequential patrimonial rights — including those of a restitutory nature — relating to incentives for the production of energy from renewable sources unduly paid by GSE.
The case arises from a payment order obtained by GSE under Article 118 c.p.a., following the annulment, by way of self-review (autotutela) and now final, of the admission of a photovoltaic plant to the incentive scheme. In the opposition proceedings brought by the assignee of the claim, the panel raised, of its own motion, the possible lack of jurisdiction, thereby opening the constitutional debate on the question.
The question of constitutional legitimacy is said not to be manifestly unfounded, on four grounds.
(i) Breach of Article 3 of the Constitution. According to the TAR, it would be unreasonable to reserve restitutory actions to the ordinary courts, while actions for damages — including those seeking specific performance (risarcimento in forma specifica) under Article 2058 of the Italian Civil Code, which in practice serve to restore the status quo ante — remain within the jurisdiction of the administrative courts, without the limitations linked to res judicata or the unchallengeability of the measure (Article 30, paragraph 5, c.p.a.). The two remedies share the same objective: restoring the assets of the party who has suffered loss. Allocating patrimonial rights to damages and patrimonial rights to restitution to different courts therefore creates a disparity of treatment lacking any rational basis.
(ii) Breach of Articles 24, 111 and 113 of the Constitution. Excluding the restitutory remedy from the exclusive jurisdiction, once the measure has become final, would mean reducing the completeness and effectiveness of judicial protection and fragmenting the remedies available, contrary to the principle of concentration that exclusive jurisdiction is instead intended to guarantee, in accordance with the teaching of the Constitutional Court (Judgments Nos. 204/2004 and 140/2007).
(iii) Breach of Article 25, paragraph 1, of the Constitution. The new approach makes jurisdiction dependent on the choice of the party as to whether or not to challenge the forfeiture measure, thereby determining the competent court in advance on the basis of the outcome of the dispute. This, in effect, renders Article 118 c.p.a. inapplicable in the field of energy production: a payment order presupposes a right that is certain, liquidated and due, a condition which, according to the Court of Cassation, immediately vests jurisdiction in the ordinary courts. This openly conflicts with Article 133, paragraph 1, letter a), No. 2, c.p.a., which reserves to the exclusive jurisdiction disputes concerning the performance of agreements supplementing a measure (accordi integrativi di provvedimento), such as the ancillary agreements (convenzioni accessorie) attached to the grant of the incentive (Constitutional Court, Judgment No. 16/2017).
(iv) Breach of Article 103, paragraph 1, of the Constitution. Exclusive jurisdiction, in the “particular matters” identified by law, may by its nature also extend to subjective rights closely linked to the exercise of administrative power. In the field of energy production, GSE acts as an authority even when recovering incentives: a mandatory and bound activity, an expression of a munus publicum (Article 42, paragraph 3, of Legislative Decree No. 28 of 3 March 2011). Moreover, the administrative power is not exhausted by the forfeiture: other powers remain, such as the reduction (decurtazione) under Article 42, paragraph 3, of Legislative Decree No. 28/2011 and the review (riesame) under Article 56, paragraph 8, of Decree-Law No. 76 of 16 July 2020, converted into Law No. 120/2020, which confirm how closely rights and interests are interlinked. The same approach emerges from the Council of State, Plenary Assembly, Judgment No. 9 of 3 September 2019, which brought within the exclusive jurisdiction also “mere subjective rights of a patrimonial nature, only indirectly connected with the exercise of an authoritative power”, such as those asserted by way of condictio indebiti.
As to the remedy, the Order asks the Constitutional Court for an additive ruling (pronuncia additiva) and proposes three possible alternative formulations of Article 133, paragraph 1, letter o), c.p.a.: to include within the exclusive jurisdiction “restitutory” disputes, or disputes concerning “consequential patrimonial rights”, or alternatively disputes concerning “consequential patrimonial rights, including those of restitutory origin”. An interpretative ruling of rejection, or a mere cautionary ruling (sentenza-monito), would instead not be adequate: it would leave too much room for uncertainty, both as to the management of GSE’s restitutory claims and as to the procedural position of private operators.
6. Conclusions
In conclusion, the current legal landscape presents a dual track: jurisdiction of the ordinary courts for restitutory actions founded on a forfeiture that has by now become final, in accordance with the consolidated approach of the Joint Divisions of the Court of Cassation and now shared by the Council of State; and exclusive jurisdiction of the administrative courts for everything that entails the exercise, even indirect, of an authoritative power not yet exhausted.
In this context, the decision of the Constitutional Court on the question raised by TAR Lazio will therefore be decisive: a ruling upholding the question in an additive form would bring restitutory actions back within the scope of exclusive jurisdiction, whereas a rejection would definitively consolidate the allocation outlined by the Joint Divisions and already adopted by the Council of State. In the meantime, operators and GSE will need to calibrate their litigation strategies in light of this still-evolving scenario, paying particular attention to the timely challenge of forfeiture measures, which remains the decisive factor in identifying the competent court.
