Mexico’s tax and customs landscape continues to evolve at speed, with April 12–17, 2026 delivering a week of significant regulatory updates, compliance deadlines, and operational enforcement measures. For multinational groups, finance leaders, and tax teams operating in Mexico, these developments reinforce the need for proactive monitoring, accurate reporting, and strong digital controls.
In this week’s TaxSpoc Mexico Tax Update, we cover the most important changes issued by the SAT (Servicio de Administración Tributaria), including the formal release of the 2025 Tax Audit Report filing process, a major increase in individual income tax refunds, and the latest RMF 2026 amendments through the fourth and fifth advance versions.
We also highlight urgent CFDI 4.0 compliance actions, following the SAT’s update to the xslt original string file, as well as foreign trade disruptions linked to ANAM Crossing Notice (AVC) system failures affecting customs operations. In addition, we analyze the latest Supreme Court precedent on RESICO, PRODECON guidance on Article 141 tax guarantees, and critical IMSS and INFONAVIT payroll closing obligations.
This report provides practical insights and strategic actions for CFOs, tax directors, payroll teams, and compliance professionals navigating Mexico’s increasingly digital and enforcement-driven environment.
Stay ahead of Mexican tax developments with TaxSpoc’s weekly expert analysis.
Key Topics of the Week
SAT: Tax Audit Report and Refunds
Milestone of MXN 10,103 million in income tax refunds and formal call for the 2025 Tax
Audit Report
RMF 2026 — 4th and 5th Advance Versions
Three substantive changes and Annexes 1 and 2 updated for the first time in 2026
CFDI 4.0 and Foreign Trade
Critical xslt update and system failures in the Crossing Notice (AVC)
Judicial Criteria and PRODECON
New precedent P./J. 58/2026 on RESICO and technical analysis of Article 141 of the
Federal Tax Code
SAT: 2025 Tax Audit Report and Refund Milestone
Tax Audit Report – Annual Tax Opinion
On April 17, the SAT issued the formal call to file the 2025 Financial Statements Tax Audit
Report.
Deadline: May 15, 2026
Income Tax Refunds — Individuals
As of April 14, income tax refunds for individuals reached MXN 10,103 million, compared to
MXN 2,000 million the previous week.
Common causes of refund rejections include errors in bank CLABE or inconsistencies in CFDIs.
These elements should be verified before filing the anual tax return.
The exponential increase in automated refunds reflects the high efficiency of SAT algorithms, but
also raises the standard of accuracy required from taxpayers in their digital tax receipts.
RMF 2026 — 4th Advance Version: Three Substantive Changes
Published on April 14, 2026, the fourth advance version of the First Resolution of Amendments to
RMF 2026 incorporates changes derived from the reform to Article 141 of the Federal Tax Code
(Official Gazette, April 9) and includes Annexes 1 and 2 updated for the first time this year.
Rule / Article — Amendment — Effective Date
Rule 3.16.11 (amended)
Accumulation factor for foreign deposits/investments at the beginning of 2025: 0.0484. Applicable
under Article 239 of the Income Tax Regulations. Final for 2025 individual annual return.
Effective the day following publication in the Official Gazette.
Rule 11.7.3 (added)
Calculation of diesel base price for IEPS tax incentive in agricultural and fishing activities.
April 1–16: -MXN 0.28/liter
April 17: -MXN 0.60/liter
Retroactive to April 1, 2026
Rule 2.12.4 (repealed)
“Formalities for offering tax interest guarantees” repealed as a direct consequence of the reform to
Article 141. Mandatory order of priority eliminated.
Effective upon publication
5th Advance Version — First Resolution of Amendments to RMF 2026
Published: April 17, 2026 on SAT Portal
Rule 2.12.4 — Repeal
Elimination of formalities for tax guarantees as a result of Article 141 reform.
Rule 3.16.11 — Amendment
Accumulation factor (0.0484) confirmed for foreign investments. Key for individual annual returns
(deadline: April 30).
Rule 11.7.3 — Addition
Diesel base price deductions defined by period:
April 1–16: -MXN 0.28/liter
April 17: -MXN 0.60/liter
Applicable to agricultural and fishing sectors
Retroactive to April 1, 2026
Annex 1 — First Update
Official tax forms updated.
Annex 2 — First Update
Includes updated Form 60/CFF for tax guarantee processes (offering, extension, substitution,
valuation).
Transitory Provisions
Twenty-Sixth Transitory
Rule 11.7.3 applies retroactively from April 1, 2026.
Twenty-Seventh Transitory
Taxpayers with guarantees established between January 1 and April 9, 2026 may opt into the new
Article 141 regime.
Deadline: May 10, 2026
Authority response time: up to 20 business days
Failure to meet this deadline prevents access to the new guarantee regime.
CFDI 4.0 and Foreign Trade: Critical Technical Alerts
xslt Update — CFDI 4.0
On April 17, SAT updated the xslt file for the original string. Immediate action: confirm ERP
and PAC implementation. Failure may invalidate deductibility of transactions.
Transfer Monitoring
Ambiguous terms such as “support” or “gift” in bank transfers trigger atypical behavior alerts
under SAT’s audit framework.
AVC System Failures — ANAM
Intermittencies reported on April 15. Border customs operated under “Virtual” mode using
printed format and QR codes. Each incident should be documented to avoid penalties.
Customs Revenue Pressure
Despite double-digit trade growth, customs revenue declined 13% in real terms.
Nuevo Laredo: -22.7%
Manzanillo: -17%
Increased audit pressure is expected.
PRODECON, IMCP, and USMCA (T-MEC)
PRODECON — Article 141
Technical analysis confirms greater flexibility in selecting tax guarantees without proving financial
impossibility.
IMCP — Tax News
NF-72, NF-78, NF-79 address the regulatory framework and should be analyzed jointly.
Ministry of Economy & CCE — USMCA Dialogue
April 17: Joint statement ahead of the second review round, focusing on competitiveness, legal
certainty, and nearshoring.
Judicial Criteria and Social Security
Supreme Court — Precedent P./J. 58/2026
RESICO for individuals upheld. Once income exceeds MXN 3.5 million, taxpayers must transition
immediately to the general regime.
Practical implication: regime change is automatic upon exceeding the threshold, not at year-end.
Social Security — Bi-Monthly Closing
April 17 deadline for IMSS contributions and INFONAVIT payments.
Average base salary: MXN 663.5 daily
Accurate reconciliation of employee movements is critical to avoid automated tax assessments.
Strategic Summary
Four Imperatives for Senior Leadership
Tax Audit Report
Deadline: May 15, 2026. Review working papers and disclosure of executive benefits (NIF
C-13).
CFDI Technical Compliance
Ensure xslt update implementation. Non-compliance affects deductibility.
Foreign Trade Contingency
Document AVC system failures to mitigate penalties and ensure supply chain continuity.
RMF 2026 — Official Publication
4th and 5th advance versions consolidate all changes. Formal publication in the Official
Gazette expected shortly. Continuous monitoring of SAT portal is essential.