Initiative to reform the Amparo Law and its effect on tax defense

On September 12, 2025, President Claudia Sheinbaum submitted a draft decree to the Chamber of Deputies to amend and add provisions to the Amparo Law, the CFF, and the Organic Law of the TFJA. The bill, currently under legislative review, seeks to update procedural provisions, define the scope of suspension, and harmonize administrative litigation systems, particularly regarding the collection of tax credits.

Among the central points, the reform addresses: (i) the amparo trial as a judicial guarantee for the protection of fundamental rights; (ii) the scope of the legitimate interest; (iii) the effects and limits of the suspension; (Iv) the digitalization of the amparo trial; (V) the regulation of demand expansion; and (vi) strengthening mechanisms for the enforcement and execution of sentences.

In this regard, in the explanatory statement, the reform refers to legitimate interest as a constitutionally recognized concept to safeguard the fundamental rights of those governed; suspension, in relation to the consideration of the appearance of good law, social interest, and public order, specifically, the effects of suspension due to violation of social interest or public order provisions regarding the protection and intelligence of the financial system; the time limits and their sanctions in the event of noncompliance; the concept of digital protection is expressly incorporated, and mechanisms are established to reinforce compliance with procedural deadlines.

However, regarding legitimate interest, the proposal seeks to limit its admissibility by establishing that it will only exist when the impact is real, present, and distinct, and provided that the eventual resolution produces a certain and direct benefit for the complainant. In practice, this implies returning to a framework closer to traditional legal interest, as the petitioner must prove not only the ownership of a subjective right but also that the impact distinguishes them from the community. The consequence is a greater burden of proof from the filing of the claim, as well as the exclusion of cases in which diffuse or collective rights are claimed. This shift contrasts with the jurisprudential evolution of the Supreme Court following the 2011 constitutional reform, which had expanded the right to take an active standpoint based on the notion of legitimate interest to guarantee broader protection of human rights. The reform, therefore, strains the balance between the protection of fundamental rights and the demand for procedural certainty, risking violations that affect the community as a whole going unprotected.

Secondly, the initiative also seeks to restrict the extension of claims by establishing that they cannot be based on facts that were already known at the time of the initial filing. This adjustment is presented as a mechanism to avoid delaying tactics and promote thoroughness from the first written submission, but it also introduces procedural rigidity that may compromise effective access to justice. Under the current Amparo Law, the extension of claims is a necessary tool to incorporate subsequent acts or facts whose existence only becomes apparent during the course of the proceedings. Restricting its scope to assumptions "unknown" to the plaintiff may generate disputes over whether a fact was objectively known and ultimately weaken the governed's defense against the authority. If approved as per its terms, litigants would be forced to fully and in advance integrate all elements of the claim, or risk being prevented from alleging them later, which violates the principle of full access to constitutional jurisdiction.

Finally, the initiative expressly incorporates the concept of online trials, allowing for the processing of amparo proceedings through the use of electronic means for both the filing of claims and appeals, as well as for service of process and procedural management. The measure responds to the need to modernize constitutional justice, aligning it with the experience of online trials in administrative and tax matters. However, this incorporation poses challenges in terms of equal access, information security, and institutional capacity building. The right of access to justice, provided for in Articles 14 and 17 of the Constitution, requires that the use of digital tools does not result in the exclusion of those lacking technological means, nor compromise the security and protection of electronic files. Its success will depend on ensuring the interoperability, confidentiality, and availability of the platforms, as well as ensuring that legal practitioners have sufficient training to take advantage of their benefits without undermining procedural guarantees.

In conclusion, the three points analyzed reflect the tension between the legislative intention to provide the amparo trial with greater procedural order and efficiency and the constitutional need to maintain it as an instrument of broad and effective protection of fundamental rights.

Regarding tax and administrative matters, the initiative seeks to harmonize the Amparo Law with the CFF and the Organic Law of the TFJA, by providing for the inadmissibility of appeals for review and nullity judgments against acts or resolutions that resolve requests for prescription regarding tax credits determined in liquidation resolutions that have already been challenged and declared final by a competent authority, thus constituting res judicata.

Thus, while the proposal strengthens the Federation's powers over public debt and the timely collection of outstanding tax debts, it also raises questions about the scope of the limitations on suspension in tax and financial matters, as they could reduce the effectiveness of amparo as a means of defending taxpayers. In practice, this will mean that procedural strategies will focus on substantive arguments and constitutional review, while individuals will face greater restrictions in temporarily halting the execution of acts of authority.