Reform of the Amparo Law, the Federal Tax Code, and the Organic Law of the Federal Court of Administrative Justice (the “Reform”)

Main Amendments to the Amparo Law

Legitimate Interest

The Reform limits the concept of legitimate interest, requiring that the complainant prove an individual or collective legal injury that is real and distinct from that of other persons, effectively assimilating this requirement to traditional legal interest. Although this criterion existed in precedents, its explicit incorporation into the Amparo Law could result in fewer amparos being admitted or in being determined inadmissible in the Constitutional Hearing, and therefore make it more difficult for citizens to access this means of defense.

In addition, a new requirement is incorporated: that the granting of amparo generates a certain benefit and not merely a hypothetical or eventual one, which excludes indirect or future benefits previously recognized by case law.

This reduces judicial discretion to define the scope of legitimate interest on a case-by-case basis, limiting the margin of interpretation for judges. In addition, the reform omitted more recent criteria that have broadened and consolidated the understanding of the concept of legitimate interest.

In effect, legitimate interest must be an indeterminate concept, which the judge, when assessing it, can determine in each specific case.

Admissibility of Indirect Amparo Proceedings

A paragraph is added to section II of Article 107 to establish that the general rules applied in tax enforcement or collection proceedings may only be challenged by means of an amparo filed against the auction notice, and not before.

Suspension

Articles 128, 129, 135, 138, 146, 148, 166, and 168 of the Amparo Law are amended.

Since the constitutional reform of 2011, in order to grant a suspension in an amparo proceeding, the following were required: (i) the existence of the act, (ii) the appearance of a prima facie case, (iii) no effect on social interest, and (iv) no violation of public order rules.

The Reform expands the regulation contained in the Amparo Law, expressly establishing that, in order to prove its admissibility, in addition to the four above requirements, the following must be satisfied: (v) the interest in the suspension (that the contested act affects the legal sphere of the complainant), and (vi) that when weighing the effects of the suspension against the social interest and the public order and interest, possible significant damage to the community must be noted.

New grounds for inadmissibilityof the suspension are also added:

1. Administrative matter: Suspension is not admissible for the performance of activities or provision of services when there is no permit, concession, or authorization issued by the competent federal authority.
2. Financial system: In operations possibly linked to money laundering or that hinder the work of the Financial Intelligence Unit.
   
   In cases of account freezing, provisional suspension shall not be applicable, and definitive suspension may only be granted if the legality of the resources involved is proven. However, the reform guarantees that, even when accounts are frozen, access to resources necessary to cover essential needs such as salaries, pensions, and housing shall be permitted.
3. Tax matters: The suspension shall only take effect if the tax interest is guaranteed by a deposit note issued by an institution authorized by the National Banking and Securities Commission and registered with the Tax Administration Service.
4. Public Debt: The suspension shall only be granted in cases where it does not hinder the State from exercising its powers in matters of public debt.

Procedural deadlines and challenges

Restrictions are established regarding challenges, limiting their admissibility when there are indications that they are being requested for dilatory purposes:

1. Article 60 is amended to stipulate that challenges must be filed before the matter is published on the session list, except in cases of withdrawal or postponement.
2. Article 121 would limit the extension of evidentiary deadlines, except in justified cases.
3. In addition, new specific deadlines are set: 5 days to notify the admission of the appeal for review, 90 days to issue indirect amparo rulings outside of hearings, and 3.5 days to notify the admission of direct amparo.

Digital Amparo Trial

Although online trials had already been implemented by the Supreme Court of Justice of the Nation and the Federal Judiciary Council, the Amparo Law lacked express regulation. Thus, Articles 3, 25, 26, 27, 28, and 30 are amended, formalizing digital amparo proceedings as an optional alternative for complainants and mandatory for the responsible authorities.

The main changes include:

1. Electronic files and preferably electronic notifications.
2. Submissions of briefs in digital format.
3. Remote appearance of authorities.

In order to reflect these new measures, in accordance with the Fourth Transitory Provision of the Reform, the Judicial Administration Body has a period of 360 calendar days to make the necessary adjustments to the Federal Judiciary's Electronic System, as well as a period of 180 calendar days to issue a General Agreement regulating electronic files.

Expansion of the claim

The grounds for extending the claim are restricted, establishing strictly that it will only proceed in the cases expressly recognized in Article 111 of the Amparo Law, that is, when the legal deadline for filing the claim has not expired or with respect to facts unknown at the time of its filing, provided that they are directly related to the acts claimed in the original claim.

Enforcement of judgments

Article 192 of the Amparo Law adds the obligation for judges to analyze in advance the competence of the authority to enforce judgments, whether the responsible authorities or others considered to be linked to the enforcement of the judgment.

Pending Amparo proceedings.

The Reform establishes, in its Third Transitory Provision, that, as it is a procedural law, the procedural stages already completed that generate acquired rights will be governed in accordance with the applicable provisions in force at the time of their commencement. However, it states that those procedural actions subsequent to the entry into force, i.e., as of October 17, 2025, will be governed by this Reform.

This means that new proceedings, such as the review of a suspension previously granted for the benefit of a citizen, could be invalidated when the corresponding appeal is resolved under the new parameters governing suspension in the Reform.

In other words, it would be applied retroactively with possible harm to citizens, which is a clear violation of the principle of non-retroactivity of laws protected by the Federal Constitution.

Reforms to the Federal Tax Code and the Organic Law of the Federal Court of Administrative Justice

The Reform modifies Article 124 of the Federal Tax Code and Article 3 of the Organic Law of the Federal Court of Administrative Justice.

This would establish as grounds for dismissal of the appeal for revocation and the contentious-administrative proceeding the challenge of acts within the administrative enforcement procedure relating to final tax credits or requests for prescription, as well as against those administrative acts that the taxpayer claims to be unaware of.

Consequently, taxpayers must go directly to the amparo proceeding to challenge such acts.

Conclusion

The Reform introduces significant changes to amparo proceedings and tax litigation in Mexico.

On the one hand, it limits access to amparo by redefining legitimate interest, which will likely reduce the number of cases admitted or, in those cases where they are admitted, result in dismissal for lack of interest. This will consequently weaken this constitutional control mechanism as a means of defense.

On the other hand, the conditions for the admissibility of suspension in key matters are tightened, shifting the burden of proving the legality of their actions or remedies to the individual, and making such protection subject to more onerous guarantees and greater legal requirements. These changes imply higher procedural and economic costs for taxpayers and individuals.

In addition, the express regulation of digital amparo proceedings institutionalizes practices already implemented by the Federal Judiciary, which may improve efficiency and access, although it also poses challenges in terms of technological infrastructure and personal data protection.

However, it should be noted that this modernization of the amparo trial will benefit individuals, as in some cases the responsible authorities did not have access to electronic notifications, which made it too slow to notify them of proceedings. Streamlining this means of constitutional control is essential for its effectiveness.

Overall, the reform strengthens the authorities' control over proceedings and reduces the scope for defense by individuals, creating a more rigid, restrictive, and costly system that, to a certain extent, violates the constitutional principle of non-retroactivity of laws. Therefore, from now on, both individuals and authorities will have to anticipate and, in many cases, rethink their actions and strategies within a framework of greater procedural, economic, and evidentiary requirements.

Authored by Marino Castillo Moreno, Andrea de los Santos, Andrea Perez, and Alejandro Gómez.