Tax credit

Zes Unica and Transition 5.0, cumulation according to final enterprise size

The clarifications provided by the Revenue Agency on Monday 23 June in response to interpello 168/2025

by Marco Belardi

23 June 2025

3' min read

Key points

Crystallising the corporate dimension: the time node
Transition 5.0: Agency declares itself incompetent
Double funding: the fine line of cumulation
Between legal certainty and operational complexity

3' min read

The Revenue Agency's reply no. 168/2025 of 23 June addresses two crucial issues for companies wishing to cumulate the Zes Unica tax credit with the Transition 5.0 tax credit: when does the company size crystallise and how does the ban on double financing apply. A relevant technical analysis in view of the upcoming deadlines.

Crystallisation of company size: the time node

The most important clarification is on when the size of the company - medium or large - is to be determined for the purpose of accessing the differentiated rates of the Zes Unica credit. The question arises from the case of a company that has already submitted ex ante communications as a medium-sized enterprise, but which, with the approval of the 2024 budget, will exceed the size parameters and become a large enterprise.

The answer is straightforward: 'For the purposes of the 2025 SEZ tax credit, the applicant will have to verify its size (following the approval of the 2024 budget) when sending the supplementary communication', i.e. the ex post communication.

Therefore, it is not the size at the time of the first communication (31 March - 30 May 2025) that matters, but the size at the time the supplementary communication is sent (18 November - 2 December 2025). This makes it necessary to update the data and recalculate the benefit according to the final size status, possibly waiving the higher incentives for SMEs.

It is to be hoped that the supplementary communication model allows for the change of size: the 2024 model did not.

Transition 5.0: Agency declares itself incompetent

On the Transition 5.0 credit, the Agency declares itself incompetent: 'the relevant identification [of company size] is not within the competence of the writer, as it does not concern any tax provision'. The management of the credit, in fact, is entrusted to Mimit and Gse.

This answer is not only formal: it confirms that the measure falls within the perimeter of energy transition aid and has its own rules, different from the fiscal ones, but leaves unresolved the question of what size should be taken into account in the case of changes during the year.

Double financing: the fine line of cumulation

The second question of the interpellation concerns the prohibition of double financing, especially in the case of cumulation between Zes Unica credit (financed with non-Pnrr resources) and Transition 5.0 credit (financed with Pnrr resources). The petitioner proposed to apply it only if both measures are covered by Pnrr funds.

Here, too, the Agency calls itself out: 'the issue raised [...] was examined by the Ragioneria Generale dello Stato [...] in circular No 33/2021'. According to this circular, the prohibition must be interpreted taking into account the rules on European funds and the NRP. In essence, cumulation is allowed only within the limits of the total eligible cost, even if one of the two measures is non-Pnrr.

The principle, therefore, cannot be circumvented: it remains mandatory to ensure that expenses facilitated with Zes Unica credit are not already covered by Transition 5.0 credit and vice versa. The beneficiary enterprise will have to set up appropriate traceability and reporting systems.

Between legal certainty and operational complexity

Having clarified some important aspects, the reply confirms the fragmentation of competences between Revenue, Mimit, Gse and the General Accounting Office. With an increase in procedural complexity for companies, especially in cases of cumulation.

The fact that size was not 'crystallised' at the date of the original communication introduces a relevant variable in business strategies: the transition from SME to large enterprise will have to be carefully monitored and its effects on the facilitation assessed.

On double financing, the onus is not only technical, but also managerial: it requires continuous monitoring and precise reporting.

The clarifications, albeit partial, are a step forward. But the need for more effective regulatory and operational coordination remains.