Reporting Period: October 19–24, 2026
A comprehensive overview of the regulatory amendments, judicial precedents, and administrative measures with the greatest potential impact this week. This report prioritizes developments according to their strategic relevance to your organization.
8 Priority Topics
Introduction & Agenda
What Does This Report Cover?
The week of October 19–24, 2026, saw a concentration of tax, customs, and financial regulatory developments. The following topics are ranked from highest to lowest strategic impact:
- Customs Law Reform — New precautionary seizure powers for undervaluation. Effective January 1, 2027.
- Supreme Court of Justice (SCJN) — Key Binding Precedents — RESICO, residential rents, and digital lease registration.
- 2026 Miscellaneous Tax Resolution (RMF) — Fourth Amendment, Third Advance Version — El Buen Fin incentives, diesel reference price, and annex amendments.
- Financial Intelligence Unit (UIF) / FATF / Financial Intelligence — Mutual Evaluation and UIF–National Guard Agreement.
- Official Gazette (DOF) — Article 69-B of the Federal Tax Code (CFF) and Countervailing Duties — Presumption lists, nullified proceedings, and ceramic coating reviews.
- Ministry of Economy / National Customs Agency of Mexico (ANAM) / Ministry of Labor and Social Welfare (STPS) / Taxpayer Defense Ombudsman (PRODECON) — Domestic content, 24/7 operations at Manzanillo, USMCA labor matters, and income tax treatment of pensions.
- Additional SCJN Procedural Precedents — Direct amparo proceedings and labor litigation.
- PRODECON — Income Tax Treatment of Pension Payments — SAT’s position on retroactive IMSS pension payments.
Priority Topic #1 | DOF — October 23, 2026
Customs Law Reform: Precautionary Seizure for Undervaluation
The Decree published in the Official Gazette of the Federation (DOF) on October 23, 2026, effective January 1, 2027, introduces significant changes to the precautionary seizure framework and customs valuation reviews. This is undoubtedly the regulatory change with the greatest operational implications for importers and customs brokers.
Article 144 — Ex Officio Initiation of Verification Powers
If the value declared in the customs entry (pedimento) is lower than the transaction value of identical or similar goods, as determined under Articles 72 and 73, the customs authority will initiate verification powers ex officio, without requiring a request from the importer.
Article 151, Section VII — New Ground for Precautionary Seizure
The declaration of a value below the transaction value of identical or similar goods, determined in accordance with the valuation methods established under the Customs Law, is expressly added as a ground for precautionary seizure.
Article 154 — Thresholds and Substitution of Security
- Difference below 20%: The importer may substitute the seizure by making a cash deposit or providing a customs guarantee account covering the taxes and countervailing duties attributable to the difference.
- Difference of 20% or more: Only a cash deposit is permitted.
Article 177, Section XII — Presumption of Tax Fraud
Where a verification procedure establishes that an importer operating under an exemption regime declared a value at least 20% below the value of identic
al or similar goods, and this resulted in the omission of foreign trade taxes, a presumption of tax fraud arises.
Operational provisions specifying the goods concerned and the applicable percentages must be published in the DOF no later than December 31, 2026. Actively monitor the secondary rules and implementing provisions.
Priority Topic #2 | SCJN — Judicial Weekly Publication, October 23, 2026
Supreme Court: Three Binding Judicial Precedents
On October 23, 2026, the Plenary of the Supreme Court of Justice of the Nation (SCJN) published three binding judicial precedents, which become mandatory on Monday, October 26, 2026. Their implications extend to the RESICO tax regime, the residential rental market, and personal data protection.
P./J. 209/2026 — RESICO | Highest Tax Impact
Failure to make three or more monthly payments within a calendar year, whether consecutive or not, or failure to file the annual tax return, triggers an automatic and immediate change of tax regime without requiring an administrative act by the tax authority.
Any notice issued by the authority is merely informational and serves purposes related to legal defense. The precedent resolves a conflict of criteria between the SCJN’s First and Second Chambers.
P./J. 210/2026 — Limit on Rent Increases
Article 2448 D of the Mexico City Civil Code, which caps annual rent increases at the inflation rate published by Banco de México, is constitutional.
The provision satisfies the proportionality test under deferential scrutiny. It protects the human right to adequate housing, helps prevent gentrification, and does not eliminate contractual freedom. The precedent becomes binding on October 26, 2026.
P./J. 211/2026 — Digital Lease Registration
The Digital Lease Agreement Registry is subject to a constitutionally conforming interpretation under the Political Constitution of the United Mexican States (CPEUM). Only the neighborhood (colonia), borough (alcaldía), rent amount, and rent increase may be registered.
The following information is excluded from registration: names, tax information, bank accounts, guarantees, guarantors, and descriptions of the property.
Priority Topic #3 | 2026 RMF — Fourth Amendment
2026 Miscellaneous Tax Resolution: Third Advance Version of the Fourth Amendment
Published on the SAT website on October 22, 2026, this advance version takes effect in accordance with Rule 1.3 of the Miscellaneous Tax Resolution (RMF). It addresses three principal areas with immediate implications for businesses participating in El Buen Fin and for the diesel industry.
1. El Buen Fin Incentives — Chapter 11.4, Rules 11.4.1–11.4.10
Chapter 11.4, governing the El Buen Fin raffle, has been amended. Key provisions include:
- Permanent fund offsets between the Federal Government and state governments to cover local taxes on prizes.
- State governments must remit to the Ministry of the Interior (SEGOB) the government revenues (aprovechamientos) arising from unclaimed prizes. Compliance may be documented using filing form 3/DEC-3.
- Financial institutions may credit the incentive against their own income tax (ISR) or tax withheld, in provisional, final, or annual payments, once notified by the SAT through the Tax Mailbox (Buzón Tributario).
2. Diesel Reference Price — Rule 11.7.3, New Sections XXVII, XXVIII, and XXIX
Specific per-liter deductions are established for the following dates:
- October 8: Deduct MXN $1.06 per liter.
- October 15: Deduct MXN $1.09 per liter.
- October 22: Deduct MXN $1.11 per liter.
These deductions directly affect the calculation of the Special Tax on Production and Services (IEPS) applicable to diesel during the reporting period.
3. Annex Amendments
The following amendments are approved:
- Second Amendment to Annex 1 of the 2026 RMF.
- Third Amendment to Annex 2 of the 2026 RMF, updating procedural filing forms.
- Fourteenth Amendment to Annex 15 of the 2022 RMF, updating tax tables for manufactured tobacco products.
The advance versions take full effect in accordance with Rule 1.3.
Priority Topic #4 | UIF / SHCP — October 2026
Financial Intelligence Unit: FATF Evaluation and Agreement with the National Guard
Mexico–FATF Mutual Evaluation: Final Stage
Mexico is in the final stage of the Financial Action Task Force’s (FATF) Fifth Round of Mutual Evaluations. FATF directly evaluates Mexico, unlike certain other Latin American countries that are evaluated by GAFILAT.
The decisive Plenary meeting will take place from October 26–30, 2026.
The evaluation covers the Mexican State as a whole, including supervisory authorities, law enforcement and justice institutions, security authorities, and both the financial and non-financial private sectors. The evaluation team’s on-site visit took place in March 2026.
The outcome will determine the effectiveness rating of Mexico’s anti-money laundering system in the eyes of international markets.
An unfavorable FATF rating could affect the cost of international financing and the reputation of Mexico’s financial system.
UIF–National Guard Agreement
Signed on October 13, 2026, the agreement establishes mechanisms for the timely exchange of information to prevent and detect transactions involving resources of illicit origin (Operaciones con Recursos de Procedencia Ilícita, ORPI).
The National Guard will share databases with the UIF, while the UIF will generate and share intelligence products derived from reports submitted by obligated entities.
The agreement includes:
- Training in operational and strategic analysis.
- A coordination and monitoring working group.
- Protection of personal data and classified information.
- Restrictions on using the information for purposes outside the parties’ institutional mandates.
Priority Topic #5 | DOF — October 23, 2026 | Article 69-B of the CFF
Article 69-B Lists: Presumptions, Nullified Proceedings, and Legal Effects
On October 23, 2026, the DOF published three SAT notices concerning Article 69-B of the Federal Tax Code (CFF), which addresses the issuance of invoices for transactions presumed to be nonexistent (EFOS). The notices have different legal consequences for the taxpayers involved and their counterparties.
Notice 24395 — Rulings Set Aside Under the Pre-July 24, 2018 Regime
The notice reports that taxpayer SOSA MENDOZA MATILDE (SOMM630314TN5), who was included in the final list published on November 13, 2018, obtained an unrestricted annulment (nulidad lisa y llana) through Annulment Proceeding No. 848/23-14-01-9, decided on January 27, 2024, by the Pacific Regional Chamber of the Federal Court of Administrative Justice (TFJA).
The Article 69-B proceeding is rendered without effect. However, the tax authority retains its powers with respect to other tax invoices.
Notice 24396 — Eight Taxpayers with Proceedings Rendered Without Effect Under the Current Regime
Eight taxpayers, including Softtek Tecnología en Información, Electro Riegos, Furaga, and Grupo Bourson, obtained annulment judgments from various TFJA chambers. The Article 69-B proceedings initiated against them are therefore rendered without effect.
Important: The annulment does not exempt the taxpayers from liability in connection with other invoices issued without the material capacity to perform the underlying transactions. The tax authority’s audit powers remain fully intact.
Notice 24732 — New Consolidated Presumption List: 171 Taxpayers
The SAT has issued a consolidated notice to 171 taxpayers, both individuals and legal entities, informing them that they fall within the presumption framework under Article 69-B of the CFF because they issued invoices without the assets, personnel, infrastructure, or material capacity required to conduct the invoiced activities.
Response deadline: 15 business days from the date the final notification takes effect. Taxpayers must submit a free-form written response to the authority that issued the corresponding individual notice.
Taxpayers that have deducted expenses or claimed VAT credits on transactions with any of the 171 notified EFOS should immediately assess their tax exposure and consider filing amended tax returns.
Priority Topics #6–8 | SAT · Ministry of Economy · STPS · PRODECON · ANAM
Key Updates: SAT, Economy, Labor, Customs, and Taxpayer Defense
SAT — Mobile Offices and New Appointment System
From October 19–23, the SAT deployed mobile service units across 46 municipalities in 21 states, targeting 17,077 procedures and 8,150 individuals served.
In addition, a new electronic appointment system was introduced for audit, foreign trade, and tax collection procedures. Services include guidance on VAT and income tax refunds, restrictions on digital tax seals, installment payments for outstanding tax liabilities, and the application of incentives under the Federal Revenue Law (LIF).
More than 10,000 procedures for businesses are handled each week.
Ministry of Economy — Domestic Content in the Energy Sector
Secretary Marcelo Ebrard presented a new methodology for measuring and certifying “Made in Mexico” content in the hydrocarbon, electricity, and biofuel sectors.
The verification period will be reduced from 18 months to 90 calendar days.
The 320 certifications projected under the initiative would increase domestic content from 35% to 40%, equivalent to USD 60 billion over the period.
The methodology incorporates energy justice, gender equality, and the digitalization of administrative procedures.
ANAM — 24/7 Operations at the Port of Manzanillo
The Manzanillo Customs Office in Colima will operate continuously, 24 hours a day, from October 26–30, 2026, to clear cargo backlogs caused by hydrometeorological events and restore the port’s logistics chain.
The measure was communicated to ASIPONA, UCE, customs brokers, and maritime transport companies.
It has a direct operational impact on importers and exporters connected to the Port of Manzanillo.
STPS — USMCA Labor Matters and Volkswagen
Successful closure of USMCA Rapid Response Labor Mechanism (RRM) cases: The cases involving Alimentos Grole in Cajeme, Sonora, and Amphenol Optimize México in Nogales, Sonora, were successfully closed. Remediation plans included reinstatement, back-pay settlements, training, and zero-tolerance policies.
Additionally, Volkswagen de México and the SITIAVW union signed an agreement that averted a strike scheduled for October 22, with support from the STPS and the Federal Center for Labor Conciliation and Registration (CFCRL).
Additional SCJN Precedents and PRODECON | Procedural Matters and Taxpayer Issues
Procedural SCJN Precedents and PRODECON: Income Tax Treatment of Pensions
Procedural Precedents — Collegiate Circuit Courts
Precedent III.1o.T.2 K (12a.) — Ineffective Grounds of Challenge in Direct Amparo Proceedings
Arguments concerning matters that were not raised in the original proceedings—for example, outsourcing or insourcing arguments introduced for the first time in a direct amparo action—are deemed ineffective.
The Collegiate Court cannot step into the role of the responsible authority to analyze issues that were not part of the original dispute.
Practical takeaway: The legal defense strategy must be developed from the original proceedings, rather than introduced for the first time at the amparo stage.
Precedent III.1o.T.10 L (12a.) — Job Offer: Procedural Forfeiture
The appropriate procedural stage for offering reinstatement or continued employment in ordinary labor proceedings is when answering the complaint. If the offer is not made at that stage, the right to make it is forfeited.
A late offer made during the oral hearing, if rejected, does not limit the employee’s entitlement to back pay or invalidate the reinstatement claim.
This precedent has implications for companies’ labor litigation management.
PRODECON — Income Tax on Pensions: SAT’s Position
PRODECON identified an issue in the individual annual tax return application: retroactive IMSS pension payments made as a lump sum are aggregated into a single tax year. As a result, the exemption under Article 93, Section IV, of the Mexican Income Tax Law (LISR) is limited to 15 annual Measurement and Update Units (UMA) for one tax year, without allocating the amount across the years in which the pension payments accrued.
SAT’s position: Article 171 of the LISR Regulations applies only when an employee agrees with the employer to receive payment in a single lump sum. A retroactive payment arising from a court ruling does not acquire the legal nature of a lump-sum payment; it retains its character as a periodic payment.
Accordingly, the exemption is applied subject to the daily limit under Article 93, Section IV, and the exempt-income field in the electronic filing application remains locked against modification.
Affected taxpayers should assess available legal remedies to ensure that the exemption is correctly applied for each year in which the pension amounts accrued.
Conclusions and Immediate Action Items
The week of October 19–24, 2026, marked a turning point in Mexico’s tax and regulatory environment. These are not routine updates; they are developments requiring decisions now, not later.
1. Audit Import Transactions Now
With the Customs Law reform taking effect on January 1, 2027, any transaction in which the declared customs value is below the value of identical or similar goods may be subject to precautionary seizure.
Conduct a customs valuation compliance assessment before year-end.
2. Review RESICO Status
A change of tax regime resulting from non-compliance is automatic and immediate. If a taxpayer has missed three monthly payments or failed to file the annual tax return, the taxpayer is already outside RESICO.
The tax and potential criminal consequences may be severe. Act urgently.
3. Assess Exposure to Article 69-B Lists
With 171 additional taxpayers included in the EFOS presumption list, review whether any of your clients’ suppliers appear on the list.
The 15-business-day response period is non-extendable. Failure to act may jeopardize the deductibility of expenses and the recovery or crediting of VAT on the affected transactions.
4. Monitor the FATF Mutual Evaluation Outcome
The Plenary meeting scheduled for October 26–30 will determine Mexico’s rating. The outcome may have immediate implications for the country’s anti-money laundering framework and the obligations of regulated and other obligated entities.
Anticipate potential adjustments to compliance programs.
