Mexico approves historical amendment to the Amparo Law: new limitations, requirements and digital justice system

Some of the key aspects to this amendment are as follows:

Legitimate interest

Legitimate interest is a standing requirement so that an individual or group may file an amparo proceeding against acts or omissions by authorities that infringe upon their human rights, due to their specific standing within the legal framework. This enables access to justice for rights with collective impact (e.g., freedom of expression, access to information, a healthy environment, a life free from violence), especially in regard to civil organizations that advocate for vulnerable groups.

Currently, several aspects of legitimate interest are recognized in court precedents, but the law only established two main elements: i) individual or collective in nature, and ii) arising from the complainant’s special standing within the legal order.

However, Article 5 of the Amparo Law was amended, so that in order to demonstrate legitimate interest, the complainant must show:

1. A real, current, and differentiated legal injury compared to others.
2. That nullifying the challenged act yields a certain and direct benefit, not merely hypothetical or eventual.

According to the Legislative Intent Statement, this aims to prevent speculative litigation or cases lacking a clear legal nexus. However, it may hinder the protection of collective rights that do not confer direct benefits to the complainant, such as environmental or access to public information rights.

Furthermore, it may also restrict access to justice in collective actions under international standards, particularly regarding environmental matters.

Suspension of the challenged act

Previously, suspension in amparo proceedings required only i) a request by the complainant, and ii) non-contravention of public interest or public order.

Under the reform, courts must now also verify the following:

1. Certainty of the challenged act. Preliminary evidence of its existence.
2. Suspensional interest. Proof that denying the suspension would harm the complainant.
3. Weighing the suspension against public interest and order.
4. Prima facie case, meaning a preliminary assessment on whether the arguments and elements submitted by the complainant show the existence of the right being claimed.

Additionally, suspension cannot be granted when it would harm public interest or contravene public order, as in the following cases:

• Operations potentially linked to money laundering. In this case, it is not ruled out that a definitive suspension may be granted if the legality of the resources is proven to the authorities, but provisional suspension is barred. It is important to note that, in any case, the judge must safeguard the necessary resources to guarantee the minimum level of subsistence, alimony obligations, payroll payments, and tax assessments.
• When it allows activities or services requiring federal permits to continue when the complainant lacks such permits.
• When it obstructs the State in matters of public debt.

On the other hand, the reform establishes that in the case of tax credits that were challenged and considered final and binding by a competent authority, the suspension may be granted at the court’s discretion. However, this suspension will only take effect if the determined amount is guaranteed through a deposit certificate or a letter of credit issued by one of the authorized institutions, in accordance with the general rules issued for such purpose by the Tax Authorities, as well as other applicable legal provisions.

It is important to note that the guarantee of tax liability could be significantly modified if the proposed reform to the Federal Tax Code included in the 2026 Economic Package Bill is approved. Under this reform, a mandatory sequence must be observed and exhausted in all cases to obtain a suspension of the administrative enforcement proceedings. This order would be as follows: First, the posting of a deposit bond; second, once this option is exhausted to the extent allowed by the taxpayer’s financial capacity, a letter of credit may be provided; third, a pledge or mortgage could be constituted, then a security bond, followed by joint liability, and finally, administrative attachment.

Lastly, in cases concerning mandatory pretrial detention, suspension may only be granted to ensure the complainant remains at the disposal of the amparo court.

Admissibility of amparo in tax matters

Amparo proceedings in tax matters (specifically against collection efforts and enforcement of final tax credits) can no longer be filed at any stage. If the tax credit has been confirmed by a competent authority or there are rulings on its statute of limitations, amparo may only be filed upon publication of the auction notice.

Only at that point can the complainant assert: i)procedural violations, and ii) any challenges to general norms applied during the procedure.

Simultaneously, the Organic Law of the Federal Court of Administrative Justice was amended to consider as inadmissible any claim challenging resolutions which order the payment of a tax credit, which has already been contested and determined as final and binding through a resolution of the competent authority, as well as acts resolving requests for the statute of limitations concerning such credits.

The same grounds were incorporated as a cause for inadmissibility to file the administrative appeal for revocation under the Federal Tax Code, as well as in cases when the taxpayer claims to be unaware of the administrative act.

Digital amparo proceedings

The reform strengthens online amparo proceedings, as a way to ease access to justice via electronic means. It also mandates authorities to appear before the court through these digital means.

Key changes include:

• Legal recognition and enhancement of electronic filings and digital signature.
• Courts are no longer required to ensure full consistency between digital and physical case files; the integration of said case files will now be regulated by the Judicial Administration Body.
• Authorities must have user accounts on the Online Services Portal.

Procedural deadlines

New deadlines are established for both complainants and judicial bodies:

• The maximum non-extendable deadline to issue a judgment on the case is now 90 calendar days.
• Judges must notify the admission of review appeals within 5 days.
• Frivolous recusals will be sanctioned; further, admissibility of said recusals now requires that the case is not listed for hearing by the Collegiate Court.
• Deadlines for submitting evidence are restricted to the first appointed date for the Constitutional Hearing, regardless of later postponements, except when it concerns facts previously unknown to the parties.

Expansion of the complaint

Expansion of the complaint is only permitted if the challenged act was unknown at the time of the original filing. Judicial discretion is eliminated for cases not covered by Article 111 of the Mexican Amparo Law, aiming to prevent procedural delays.

Compliance with judgments

Judges must first assess whether the responsible authorities have the legal capacity to comply with the judgment. The reform also reinforces the notion that authorities may argue legal or material impossibility to comply, shielding them from sanctions or criminal liability.

Although the original proposal sought to eliminate automatic sanctions and limit them to the designated authority (not its head), this was removed in the Senate’s committee report.

Retroactive application and transitional regime

The reform will take effect one day after its publication in the DOF (as of October 17, 2025).

The Judicial Administration Body is granted 360 calendar days to adapt the Judicial Electronic System, and 180 calendar days to issue a General Agreement regulating integration of electronic and physical case files.

Regarding retroactive application, the final text differs from the original draft. Previously, all pending cases were to be processed under the new law.

Currently, the Third transitional provision states:

“THIRD. As this is a procedural law, completed procedural stages that have generated acquired rights shall be governed by the legal provisions in force at the start of the respective proceedings. Subsequent procedural actions shall be governed by this Decree, in accordance with the doctrine and jurisprudence of the Supreme Court of Justice of the Nation, without implying retroactive application or infringement of acquired rights, as they pertain to future actions.”

Thus, the transitional regime applies the principle that concluded stages of the court proceedings follow prior law, while future actions adhere to the new provisions.

However, the reform also introduces substantive changes, such as stricter requirements for granting a suspension and new admissibility rules in tax matters. Applying these to ongoing proceedings constitutes retroactive application, which violates Article 14 of the Mexican Constitution, since the applicable provisions applicable a judicial must be those in force at the time a party becomes bound by or subject to it, that is, when the process begins, Therefore, it is important remain alert on how this Third Transitional provision is applied in practice.