Tax returns and errors: clarifications from the Court of Cassation in Order no. 28398 of 2025 regarding the terms for amendment

A tax return is not an act of extrajudicial confession, but rather a declaration of knowledge and judgment. Consequently, it must be possible to amend it if the taxpayer, due to an error of fact or law, has indicated elements that do not correspond to reality, resulting in a tax burden higher than that provided for by law. However, the correction of such errors must contend with precise temporal and procedural limits. The Court of Cassation addressed this delicate issue with Order no. 28398 of 27/10/2025, providing a clear and summary framework of the protections available to the citizen.

The distinction between errors in favor of the Administration and in favor of the taxpayer

The ruling in question, issued by the Tax Section under the presidency of C. R. and the report of F. M. M., addresses the dispute between the taxpayer M. R. and the State Attorney's Office. The judges of legitimacy reiterated the fundamental distinction between the two types of supplementary returns, depending on whether the error committed benefits or harms the Treasury. If the error resulted in a lower payment of taxes (damage to the Public Administration), the return may be supplemented within the limitation periods established for assessment. Conversely, if the error penalized the taxpayer, the path of ordinary integration with immediate offsetting is narrower, but does not preclude other avenues for recovery.

In the event of errors or omissions in the tax return, the supplementary return may be filed no later than the deadlines referred to in Art. 43 of d.P.R. no. 600 of 1973, if intended to avoid damage to the Public Administration (Art. 2, paragraph 8, of d.P.R. no. 322 of 1998), whereas, if intended, pursuant to the subsequent paragraph 8-bis, to amend errors or omissions to the detriment of the taxpayer, it is subject to the deadline for filing the return for the subsequent tax period, with offsetting of any resulting credit, it being understood that the taxpayer may request a refund within forty-eight months of payment and, in any case, oppose, in litigation proceedings, the higher tax claim of the Financial Administration.

The taxpayer's channels of protection: refund and legal defense

As highlighted in the principle of law reported above, a taxpayer who has made an error to their own detriment does not lose the right to recover the excess amounts paid if the deadline for filing the supplementary return for the subsequent tax period has expired. The Supreme Court emphasizes the coexistence of three different tracks of protection:

• The supplementary return route: useful for the direct offsetting of the tax credit, to be filed within the following year.
• The refund route: the ordinary action ex Art. 38 of d.P.R. no. 600 of 1973, which may be brought within forty-eight months from the payment made.
• The litigation route: the possibility for the taxpayer to oppose the Administration's tax claim in court, by pleading the error committed in their original return to neutralize the tax authority's higher demand.

Conclusions

Order no. 28398 of 2025 stands in perfect continuity with the orientation expressed by the United Sections of the Court of Cassation (judgment no. 13378 of 2016), reaffirming the principle of contributory capacity enshrined in Article 53 of the Constitution. Tax collection must always be fair and correspond to the taxpayer's actual economic situation. The decision represents a fundamental guarantee for citizens, confirming that the rigor of procedural deadlines can never translate into unjust enrichment of the State at the expense of the taxpayer in good faith.