SAT Express Audit: 24 days to prove your business activity is real

The 2026 Tax Reform introduces one of the most significant changes in recent years in the area of tax audits: a new verification authority of the SAT, recently explained by PRODECON, whose main objective is to verify that CFDIs cover real, existing, and legally valid transactions.

This authority is not minor. It marks a shift in focus: the SAT stops concentrating exclusively on the form of the tax receipt and instead focuses directly on the economic and legal substance of transactions.

What does this new authority consist of?

In accordance with Articles 29-A, section IX; 42, section V, subsection g); and 49 Bis of the Federal Tax Code, the SAT may carry out a specific on-site visit to verify that the CFDIs issued:

• Correspond to transactions actually carried out
• Derive from real legal acts
• Reflect materiality, operational capacity, and economic substance

This authority enters into force as of January 1, 2026.

Key characteristics of the verification visit

This new review has specific features that every taxpayer must be aware of:

Limited duration

• The visit will have a maximum duration of 24 business days.
• It is a one-time authority, not repeatable for the same period and facts.

Short defense period

• The taxpayer will have only 5 business days to rebut the authority’s observations, either:
• During the inspection, or
• Within the legally granted subsequent period.

Immediate suspension of CFDI issuance

• From the notification of the inspection order, the SAT may suspend the issuance of CFDIs until the final resolution is issued.

Use of technological tools

Inspectors may:

• Take photographs
• Record audio and video
• The entire procedure may be digitally documented.

Formal inspection record

• A record will be drawn up including:
• Observed facts
• Detected irregularities
• The taxpayer’s statements

Consequences if the presumption is not rebutted

Once the evidentiary period has concluded, the SAT will have 15 business days to issue a resolution. If the taxpayer fails to rebut the presumption of falsity:

• The CFDIs will be considered false for all legal purposes
• The transactions will be deemed not carried out
• They will produce no tax effects
• The Digital Seal Certificate (CSD) may be cancelled
• The taxpayer’s name and RFC may be published:
• On the SAT portal
• In the Official Gazette of the Federation (DOF)

This also directly affects clients, suppliers, and recipients of the CFDIs, who must reverse the applied tax effects.

The SAT’s real message: invoicing is no longer enough

The essence of this reform is clear:

The SAT no longer audits only documents; it audits realities.

Issuing CFDIs that are formally correct is no longer sufficient if there is no:

• Operational capacity
• Documentary evidence
• Personnel, assets, and processes
• Enforceable contracts
• Demonstrable economic substance

How to prepare for this new authority?

At AS Consulting Group, we recommend an immediate preventive approach:

Materiality diagnosis

Review whether transactions have:

• Real operational evidence
• Solid legal and commercial documentation
• Consistency between CFDIs, accounting, and operations

CFDI and process audit

Identify risks in:

• Recurring services
• Related-party transactions
• Outsourcing schemes
• International transactions

Audit response protocols

Define:

• Responsible parties
• Available documentation
• Coordinated response to the authority

The 2026 Tax Reform introduces a shorter, more direct, and more severe audit process.

The margin for reaction is minimal. The cost of not preparing can be operationally critical.

In 2026, the key question is no longer: “Is my CFDI properly issued?”

But rather: “Can I prove, today, that my transaction is real?”

At AS Consulting Group, we are ready to support you throughout this process.

For more information regarding this matter, please contact:

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We are AS Consulting Group (ASCG), a Mexican firm operating since 1991, specialized in providing comprehensive “all-in-one” services for domestic and foreign companies in Mexico, including accounting, tax, legal, labor, payroll, electronic invoicing, sustainability, technological development, real estate design and architecture, regulatory compliance, foreign investment, and business consulting. Our approach allows clients to centralize their professional needs within a single team, ensuring compliance, control, and sustainable growth of their operations. ASCG is a member firm of SMS Latinoamérica, an international network of professional firms with presence in more than 21 countries. The member firms of SMS Latinoamérica are legally independent entities that operate under their own local regulations. SMS Latinoamérica does not provide services directly and does not assume responsibility for the acts or omissions of its member firms.

The information contained in this communication is of a general nature and for informational purposes only. Neither AS Consulting Group, nor its affiliates, nor SMS Latinoamérica nor its member firms provide professional advice through this publication. Before making decisions that may affect your business, you are advised to consult a qualified professional advisor. None of the entities mentioned shall be liable for any losses or damages arising from the use of this information.

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