In 2026, Mexico’s audit environment is entering a period of greater intensity and precision. Enforcement is no longer driven primarily by “sample-based” reviews or isolated findings. Today, the Tax Administration Service (SAT) consolidates large-scale cross-checks of digital information—customs entries (pedimentos), e-invoicing (CFDI), banking data, accounting records, inventory systems, logistics documentation, supplier data, and related-party transactions—and is moving toward an electronic and increasingly predictive audit model supported by analytics, with growing references to the use of AI to sharpen risk targeting.

This context is not coincidental. Revenue targets and the design of the 2026 Economic Package are reinforcing a broader audit agenda. Under the Revenue Law and the 2026 fiscal policy framework, projected collections are approximately MXN 5.8 trillion, with meaningful increases expected in both income tax (ISR) and value added tax (VAT/IVA), and with a particular emphasis on revenues linked to foreign trade.

A recurring message in public discussions around 2026 is that foreign trade/import-related revenues are expected to grow at a significantly higher rate than other sources. Under the 2026 Revenue Law projections, import tax revenues are expected to rise from approximately MXN 151.8 billion (2025) to MXN 254.8 billion (2026)—a substantial real increase that strengthens the institutional incentive to intensify oversight of customs operations.

At the same time, tariff reforms and adjustments affecting imports from countries without trade agreements with Mexico (particularly in Asia) increase the likelihood of classification, origin, and valuation errors, adding pressure to supply chains and cost structures. New tariffs may reach up to 50% and apply across a broad set of tariff lines, including textiles, steel/iron, automotive/autoparts, plastics, among others.

In practice, the consequences of a foreign trade audit no longer end as “observations.” The most common outcomes when documentation and controls are inconsistent include:

In foreign trade, the most sensitive areas in 2026 are not only reviewed—they can trigger “domino effects” across tax, operations, and regulatory exposure.

1) Customs Value Declaration (MVE) and valuation.

Errors, omissions, or weak support in the Customs Value Declaration (MVE) frequently become the entry point for adjustments to customs value and, consequently, to import duties (IGI) and VAT (IVA)—especially where dutiable additions apply (royalties, technical assistance, freight/insurance, commissions, and similar concepts). When contractual and accounting support does not reconcile, impacts can materialize quickly.

2) Electronic file and evidence of substance.

Modern enforcement rewards well-organized evidence. If the electronic file—contracts, invoices, proof of payment, logistics documents, traceability records, and inventory integration—is incomplete or contradictory, the authority has room to disallow or reclassify the transaction.

3) Lawful stay and customs entry data integrity.

Any gap between physical goods, customs entries, inventory systems, and accounting records increases the risk of presumptions regarding unlawful stay or misapplication of the declared customs regime. This directly translates into additional duties and penalties for inaccurate declarations.

4) Returns, time limits, and inventory controls (IMMEX).

For IMMEX and certified companies, audits focus intensifies around: maximum temporary stay periods, returns (including virtual operations), inventory “discharges,” and consistency of Annex 24/30 controls. Where balances are overdue, returns lack support, or traceability is weak, the authority may conclude “non-return,” compute omitted contributions, and in certain scenarios pursue escalated legal consequences.

5) Transaction materiality (including virtual operations)

Materiality is no longer a purely “general tax” concept. In foreign trade it requires demonstrating the real operational flow—physical, documentary, and accounting—along with the business rationale for the movement. As cross-checking and predictive audits expand, tolerance for inconsistencies is declining.

6) Imported fixed assets and depreciation (a common blind spot).

A frequent issue is the absence of a reliable imported fixed-asset inventory (physical identification, linked customs entries, location, status, disposals/sales/destruction). If depreciation methodologies are applied without technical support or outside the applicable framework at the time of regularization or change of regime, the authority may reject the adjustment and recompute contributions.

7) Recharacterization or disallowance of transactions.

One of the most significant shifts in recent enforcement is that the authority is no longer limited to verifying whether a transaction “occurred,” but whether its materiality and economic substance can be demonstrated. In practice, it is not enough to have customs entries or invoices: the company must be able to articulate and document the full logic of the transaction, its business purpose, and the consistency of physical, documentary, and accounting flows.

When SAT concludes a transaction lacks materiality—often in virtual operations, internal transfers, related-party structures, or movements without clear operational evidence—the impact can be immediate and profound. The authority may disallow the transaction in its entirety, even if the goods moved physically, on the basis that economic substance was not proven.

Consequences can be high-impact:

Strategically, these findings can go beyond a single assessment: they can call into question a company’s operating and tax structure and increase the likelihood of follow-on reviews and ongoing enforcement scrutiny.

8) Inventory control and customs traceability (Annex 24 / 30).

Customs inventory control has become a central enforcement axis, particularly for IMMEX companies and high-volume operators. The authority no longer reviews isolated transactions; it reviews end-to-end traceability—from importation through return, transformation, transfer, or regularization.

Inconsistencies between:

Allow the authority to presume that goods were not returned, were not declared, or were managed irregularly. This is especially sensitive because it can replicate across entire periods, creating progressively accumulating tax exposure.

The fiscal impact can be severe:

In this sense, weak inventory controls are not only a fiscal risk—they signal weaknesses in internal control, which can expand the depth and scope of future audits.

9) Tariff classification and regulatory consequences.

Tariff classification has shifted from a technical-operational issue to an integrated regulatory risk driver. An incorrect tariff line does not only affect duty rates; it can directly impact compliance with additional regulations.

Incorrect classification may imply non-compliance with:

In these cases, errors are rarely treated as minor or easily remediable. The authority can impose automatic penalties, disallow the transaction, and assess retroactive adjustments—even if taxes were paid under a different tariff line.

10) Origin of goods and preferential tariff treatment.

Origin has become one of the most scrutinized areas, particularly amid tariff changes and global trade tensions. The authority has strengthened verification of rules of origin and supporting documentation, especially for transactions benefiting from preferential rates.

Errors in origin determination, incomplete certificates, or inconsistent documentation may lead the authority to deny preferential treatment retroactively, resulting in:

11) Consistency of electronically transmitted information.

Modern enforcement relies heavily on automated cross-checking. SAT continuously compares:

Any mismatch can generate automated alerts and trigger audits without physical visits. In this environment, errors are detected not by sampling but by large-scale analytics, significantly reducing the tolerance for inconsistencies.

The impact is systemic because:

Overall, these areas share a common element: they do not generate isolated impacts; they create chain reactions that can escalate from tax adjustments into operational disruption and strategic exposure. In today’s environment, lack of control and traceability is interpreted as fiscal risk—and the cost of reacting late is often materially higher than the cost of prevention.

The increase in enforcement pressure is not merely cyclical; it reflects a structural change in the way the authority conducts audits. SAT now has unprecedented access to integrated digital and electronic data sources that previously operated in silos and are now increasingly consolidated.

The authority has near real-time access to:

• Customs entries and foreign trade operations
• CFDI for income, expenses, and payroll
• Electronic accounting
• Inventory, returns, and fixed-asset reporting
• Banking and financial information
• Tax returns and amended filings

The increase in enforcement pressure is not merely cyclical; it reflects a structural change in the way the authority conducts audits. SAT now has unprecedented access to integrated digital and electronic data sources that previously operated in silos and are now increasingly consolidated.

The authority has near real-time access to:

• Differences between customs declarations and what is reported in CFDI or accounting
• Inventory and return inconsistencies
• Atypical use of tax benefits
• Valuation, origin, or classification patterns that deviate from sector benchmarks

This data-driven model is reinforced by revenue targets and the fiscal adjustments expected in 2026, which increase the incentive to prioritize efficient revenue sources. In this context, foreign trade becomes a priority area because it allows for immediate adjustments to duties, taxes, tariffs, and applied benefits.

As a result, the probability of review increases significantly—not necessarily due to company size, but due to the company’s digital compliance profile. Organizations with accumulated inconsistencies, fragmented controls, or non-reconciled information are more exposed to successive requests and deeper audits.

In short, audit pressure is increasing because enforcement no longer depends on manual detection of errors; it depends on a digital ecosystem that automates taxpayer selection. The risk is no longer limited to “non-compliance,” but to the inability to prove compliance consistently and electronically.

In today’s environment, waiting for an audit to “get the house in order” is no longer viable. The authority’s integrated data, automated cross-checking, and risk-selection models can identify inconsistencies before a taxpayer is even notified. Late reaction not only increases tax cost, but also amplifies legal and reputational exposure.

The standard that genuinely reduces exposure in 2026 is institutionalizing preventive audits—not as isolated reviews, but as a continuous system of internal control and verification for tax and customs compliance. This is increasingly critical given that issues once treated as administrative may escalate into allegations of tax fraud, smuggling, or equivalent offenses, with potential criminal implications for executives, legal representatives, and administrators.

A robust preventive audit typically includes:

The goal is not merely to comply, but to be able to prove compliance immediately, consistently, and in a format that is electronically verifiable under today’s data-driven enforcement standards.

In an enforcement environment that is increasingly technical, digital, and exposed to fiscal, operational, and even criminal implications, compliance management cannot be delegated to isolated reviews or reactive approaches. It requires an integrated, methodical, and proven framework capable of anticipating risks and sustaining compliance under progressively targeted audits.

ST Stratego supports organizations through an integrated Compliance 360 model designed to prevent contingencies, protect operational continuity, and strengthen the company’s position before the authority.

Our approach is built on three pillars:

Compliance 360°

An integrated framework that provides executive visibility of risk and enables informed decision-making:

Specialized foreign trade audits.

ST Stratego is a recognized leader in foreign trade audits, with proven experience across both the private and public sectors—enabling a clear understanding of how the authority audits and how taxpayers can respond technically and defensibly.

Our services include:

Experience, methodology, and institutional trust.

ST Stratego offers:

• Demonstrated experience across the public and private sectors, delivering a comprehensive view of the regulatory framework and practical enforcement criteria.
• ISO 9001 certification, supporting quality, consistency, and continuous improvement across processes.
• A multidisciplinary team specialized in foreign trade audits, tax compliance, and risk management, with a preventive and strategic focus.