Mexico has significantly reshaped its tax compliance framework in recent years. Where the Mexican tax authorities (SAT) once relied heavily on formal documentation, they now demand something more rigorous: proof that transactions are real, supported by a legitimate business purpose and actually carried out.
The emphasis on substance-over form and rigorous verification is not a standalone initiative; it is a core component of the enforcement strategy outlined in the Mexican government’s “Master Plan.” Within this framework, the SAT has intensified efforts to combat tax evasion by strengthening audit capabilities, expanding the use of digital oversight tools and imposing stricter regulatory requirements, particularly in areas involving simulated transactions, improper invoicing practices and other high-risk compliance behaviours.
This shift has transformed the way deductions, VAT credits and even routine business operations must be substantiated. An invoice, when not accompanied by evidence demonstrating that the underlying transaction occurred and was not simulated, is no longer sufficient during a tax review.
Historically, claiming a deduction for income tax purposes or a VAT credit required meeting certain formal requirements. Many taxpayers assumed that the CFDI (digital tax invoice) was the primary and often sole piece of evidence needed for this purpose. That assumption no longer holds. During audits, the SAT consistently emphasises that a CFDI proves only that a document exists, not that the transaction itself took place and that operations are genuine.
Today, the SAT is focused on materiality and business purpose. In practice, this means taxpayers must be able to demonstrate that a transaction occurred, it relates to the taxpayer’s business activities and generated or was intended to generate a financial benefit exceeding any tax benefit obtained. Contracts, accounting records and bank statements are now merely the starting point. During audit procedures, the SAT frequently challenges the tax effects of invoices when taxpayers cannot provide additional supporting evidence, such as notarised agreements, purchase orders, emails, warehouse entry logs, delivery records, internal reports, photographs, third-party confirmations or documentation showing that the parties had the operational capacity, personnel, infrastructure or resources to execute the transaction.
These heightened requirements stem from efforts to combat practices identified in prior years where certain taxpayers issued or acquired simulated invoices to reduce their tax base. In response, Mexico introduced new CFDI regulations in 2026, under which all invoices must correspond to real, existing transactions or genuine legal acts. Any tax receipt that fails to meet this standard may be treated as false for tax purposes.
As part of this tax reform, authorities may conduct targeted in-person audits designed to verify the existence of invoiced transactions. These procedures can occur on significantly shorter timelines than traditional audits. Taxpayers must be prepared to produce supporting documentation quickly to demonstrate that invoices and operations are real and not simulated.
If the SAT concludes—based on the taxpayer’s documentation—that an invoice is false, it may suspend the taxpayer’s ability to issue digital invoices. This can cause operational disruption and create direct risks for taxpayers who may be unable to recognise deductions or VAT credits associated with those invoices. Additionally, Mexican law treats the issuance, acquisition or use of false invoices as a criminal offense, underscoring that materiality and documentation are not merely compliance matters, but critical components of risk management.
Mexico is moving toward a tax environment in which economic substance outweighs formal compliance. The 2026 reform reinforces this trajectory by pairing stricter legal requirements with faster, more effective enforcement mechanisms. In this context, taxpayers must maintain a robust, well-organised documentation file supporting both issued and received invoices, demonstrating that transactions are genuine and not simulated. Ultimately, under these reforms, any transaction that cannot be properly substantiated may be treated as non-existent for tax purposes. As explained above, the consequences of such treatment include potential operational disruptions, including restrictions on issuing digital invoices or the denial of tax effects for counterparties, such as deductions and VAT credits.
Edgar Omar Rodríguez Escareño
BDO in Mexico
The emphasis on substance-over form and rigorous verification is not a standalone initiative; it is a core component of the enforcement strategy outlined in the Mexican government’s “Master Plan.” Within this framework, the SAT has intensified efforts to combat tax evasion by strengthening audit capabilities, expanding the use of digital oversight tools and imposing stricter regulatory requirements, particularly in areas involving simulated transactions, improper invoicing practices and other high-risk compliance behaviours.
This shift has transformed the way deductions, VAT credits and even routine business operations must be substantiated. An invoice, when not accompanied by evidence demonstrating that the underlying transaction occurred and was not simulated, is no longer sufficient during a tax review.
Historically, claiming a deduction for income tax purposes or a VAT credit required meeting certain formal requirements. Many taxpayers assumed that the CFDI (digital tax invoice) was the primary and often sole piece of evidence needed for this purpose. That assumption no longer holds. During audits, the SAT consistently emphasises that a CFDI proves only that a document exists, not that the transaction itself took place and that operations are genuine.
Today, the SAT is focused on materiality and business purpose. In practice, this means taxpayers must be able to demonstrate that a transaction occurred, it relates to the taxpayer’s business activities and generated or was intended to generate a financial benefit exceeding any tax benefit obtained. Contracts, accounting records and bank statements are now merely the starting point. During audit procedures, the SAT frequently challenges the tax effects of invoices when taxpayers cannot provide additional supporting evidence, such as notarised agreements, purchase orders, emails, warehouse entry logs, delivery records, internal reports, photographs, third-party confirmations or documentation showing that the parties had the operational capacity, personnel, infrastructure or resources to execute the transaction.
These heightened requirements stem from efforts to combat practices identified in prior years where certain taxpayers issued or acquired simulated invoices to reduce their tax base. In response, Mexico introduced new CFDI regulations in 2026, under which all invoices must correspond to real, existing transactions or genuine legal acts. Any tax receipt that fails to meet this standard may be treated as false for tax purposes.
As part of this tax reform, authorities may conduct targeted in-person audits designed to verify the existence of invoiced transactions. These procedures can occur on significantly shorter timelines than traditional audits. Taxpayers must be prepared to produce supporting documentation quickly to demonstrate that invoices and operations are real and not simulated.
If the SAT concludes—based on the taxpayer’s documentation—that an invoice is false, it may suspend the taxpayer’s ability to issue digital invoices. This can cause operational disruption and create direct risks for taxpayers who may be unable to recognise deductions or VAT credits associated with those invoices. Additionally, Mexican law treats the issuance, acquisition or use of false invoices as a criminal offense, underscoring that materiality and documentation are not merely compliance matters, but critical components of risk management.
BDO Perspective
Mexico is moving toward a tax environment in which economic substance outweighs formal compliance. The 2026 reform reinforces this trajectory by pairing stricter legal requirements with faster, more effective enforcement mechanisms. In this context, taxpayers must maintain a robust, well-organised documentation file supporting both issued and received invoices, demonstrating that transactions are genuine and not simulated. Ultimately, under these reforms, any transaction that cannot be properly substantiated may be treated as non-existent for tax purposes. As explained above, the consequences of such treatment include potential operational disruptions, including restrictions on issuing digital invoices or the denial of tax effects for counterparties, such as deductions and VAT credits.Edgar Omar Rodríguez Escareño
BDO in Mexico