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Superbonus 2023, expenses over ten years with the supplementary payment

1 February 2025

3' min read

Key points

Expenditure incurred in other years
Manoeuvre intervention
The supplementary declaration
Failure to enter.

3' min read

It is the supplementary declaration of the one submitted with reference to 2023 income that is the instrument with which the Budget Law recognises, for those who have incurred superbonus expenses in the same year, the long-awaited ten-year spread (in optional form), through the new paragraph 8-sexies of Article 119 of Decree-Law 34/2020.

Expenditure incurred in other years

Before this provision, the rules established a rather singular situation, according to which:

for the super-bonus expenses incurred in 2022 (ordinarily deductible over four years) the deduction in ten annual instalments of equal amount, starting from the 2023 tax period, was made possible with an option to be made in the return to be filed in 2024 for the year 2023, provided that the first instalment of the deduction was not included in the previous year's return;
expenses incurred from 2024 onwards must mandatorily be broken down in the declaration over a ten-year period, by virtue of Article 4-bis, paragraph 4, of Decree-Law 39/2024;
nothing was envisaged for expenses incurred in 2023, for which, therefore, the only possibility remained the apportionment over four years.

The latter situation was by far the worst: many taxpayers, deprived by an increasingly rarefied market of the possibility of availing themselves of the option of credit assignment or invoice discount, risked losing (due to inability to make a declaration) all or a large part of the tax bonus, the excess of which over the period tax cannot be carried forward or claimed for reimbursement.

Manoeuvre intervention

The intervention contained in the Budget Law 2025 allows, precisely in the latter case, the option of spreading the deduction over ten years, starting from 2023 (and, therefore, without 'skipping' the first year as, instead, happened for 2022). To obviate the fact that the return for 2023 has already been filed, it has been established that the taxpayer may exercise the (irrevocable) option to spread the deduction over ten years in a supplementary return (of the 2024 Income Form or 730/2024) to be filed by the deadline for the next return (31 October 2025).

The supplementary declaration

In the supplementary declaration, the taxpayer concerned will have to replace the original deduction over four years with the more modest (but less impactful) deduction over ten years, thus obtaining a result that is unfavourable in the short term but advantageous in the medium to long term.

Those who have managed to absorb the entire deduction and assume that they will be able to do so in the next three declarations as well, will not file a supplementary return, since this is an option and not an obligation. In the event that the reduction (from 1/4 to 1/10) of the deduction of the first bonus instalment results in a higher tax liability (or, we would add, a lower credit than that already used), the difference will have to be paid, without the application of penalties and interest, by the due date of the 2024 Irpef balance.

The option should not be available to those who have not filed a declaration at all: it is, in fact, a general principle that supplementary declarations are permissible only in the presence of a validly filed original declaration. Here the remedy lies, in the writer's opinion, in submitting an original declaration within 90 days of the ordinary deadline (29 January 2025), which, for these purposes and others, should be considered as a validly submitted declaration (Article 2(7) of Presidential Decree 322/1998), then subsequently corrected by the supplementary declaration provided for by the Budget Law.

Failure to enter

Less uphill, on the other hand, seems to be the behaviour of those who have not included any deduction in their 2023 declaration form, either due to mere forgetfulness or because it was deemed unnecessary due to a lack of sufficient tax capacity. In this case, in fact, it is considered that nothing precludes the submission of a supplementary declaration, with the inclusion of the first tenth of the deduction due.