SAT Wins More Tax Cases and Boosts Collections: Mexico’s New Fiscal Balance
The tax authority is cementing its edge in the courts and preparing stricter rules for challenges, with implications for liquidity and tax planning.
Mexico’s Tax Administration Service (SAT) closed 2025 with greater dominance in final-instance tax litigation, winning 55.5% of definitive proceedings and recovering about 80% of the amount at stake—roughly 200 billion pesos—according to figures from the Ministry of Finance and Public Credit (SHCP). That shift contrasts with 2018, when the government won 48.5% of cases and recovered 73.8% of the disputed money; at that time, taxpayers obtained favorable rulings in 41.2% of matters.
Beyond the percentage of rulings, the key data point is the “size” of the economic outcome: in 2025, taxpayers won 32.9% of cases but recovered only 17.4% of the money in dispute. In practice, the authority is not only winning more—it’s winning bigger. Finance estimates that the average amount recovered per favorable ruling rose from 12.8 million pesos in 2018 to 23.5 million in 2025, an increase of about 45.5% over seven years.
This tougher enforcement strategy is part of the revenue-collection policy launched during Andrés Manuel López Obrador’s presidential term and continued under Claudia Sheinbaum’s administration: the practice of forgiving taxes for large taxpayers was eliminated, audits of prior years were intensified, and the cost of noncompliance increased through the assessment of tax credits. That has been paired with the consolidation of the SAT’s “Master Plan,” with greater use of data analytics and technology to select audits, as well as a stronger legal defense in court, according to sector specialists.
In the macroeconomic context, the focus on collection also reflects the need to fund spending commitments and preserve public-finance stability in an environment of moderate growth. Mexico has generally maintained manageable public debt compared with its emerging-market peers, but it faces pressure from debt-service costs, greater public investment needs, and social spending. With a historically narrow tax base and high informality, enforcement-driven collection has become a key component for sustaining revenue without raising broad-based tax rates.
The discussion is also taking place at a time when tax compliance is becoming more important for companies integrated into export supply chains, particularly amid “nearshoring.” For many businesses, legal certainty and tax-risk management are increasingly decisive factors in investment decisions, alongside logistics costs, security, energy, and human capital.
2026 Reforms: Challenging Assessments Will Cost More—and Hit Corporate Liquidity
One of the changes with the greatest potential impact is an amendment to the Federal Tax Code starting in 2026: when the SAT assesses a tax credit, the taxpayer will be able to pay or challenge it, but to challenge it they will have to deposit the amount of the credit via a deposit certificate at Banco del Bienestar. The measure removes commonly used alternatives for securing the government’s interest, such as surety bonds, letters of credit, or liens/seizures. Economically, the immediate effect could be a higher cost of tax litigation and a blow to liquidity, especially for mid-sized companies or groups with constrained cash flow, since “fighting” an assessment would require tying up funds before a final decision.
This new structure raises the bar for litigation and could push more taxpayers to seek settlements, self-corrections, or payments under protest to avoid having capital frozen. In day-to-day operations, it may also change tax planning and treasury management: companies with high exposure to audits may increase reserves, strengthen internal controls, invest more in compliance and documentation, or restructure operations to reduce contingencies. A secondary effect is that litigation—which for years functioned as a “valve” to defer payments while the merits were decided—would become less attractive.
From the SAT’s perspective, the incentive is clear: increase the likelihood of collection and reduce delay tactics. However, for the business climate, the challenge will be balancing collection efficiency with legal certainty, especially in complex cases involving technical interpretations of deductions, transfer pricing, VAT, input credits, or the recharacterization of transactions.
At the same time, the potential amount in dispute remains significant. The SHCP reported that as of the end of 2025 there were 203,221 disputed tax credits—i.e., subject to legal defenses—totaling more than two trillion pesos. That universe suggests that even with higher success rates, the tax authority still faces a backlog of cases with meaningful implications for future revenue and for the administrative burden on the courts and the SAT itself.
The trend is also being shaped by the growing sophistication of enforcement: data matching, digital verification, invoice traceability, and oversight of sham structures. Internationally, Mexico has aligned with stricter control practices against tax evasion and avoidance, in part due to information-exchange commitments and standards promoted by multilateral organizations. In this context, cracking down on fake invoicing and nonexistent transactions will remain a central pillar of tax policy.
The tension point remains perceptions of impartiality and the cost of accessing justice. Specialists warn that with institutional changes and a more assertive authority in the courts, taxpayers may face a more challenging landscape, particularly in high-dollar cases. The consequence could be a shift toward administrative and preventive solutions: internal audits, compliance reviews, stronger tax governance, and greater caution around aggressive interpretations.
In short, the SAT has consolidated a stronger position in tax litigation and is preparing to tighten the conditions for challenges in 2026. The foreseeable economic effect is a higher cost of disputes and a reallocation of resources toward compliance, which could improve tax revenue in the short term, but also increase demands for certainty and proportionality so as not to discourage investment or undermine competitiveness.
