Tax Materiality in Mexico: How Business Groups Should Support Their Transactions Before an SAT Review

In a group with several Mexican entities, the evidence for a single transaction is usually scattered. Legal keeps the contract, the deliverable sits in someone’s inbox, treasury records the payment and accounting books the entry. That works until the SAT, Mexico’s federal tax authority, asks the company to prove that a service was actually rendered or that goods were actually delivered. At that point there are documents, but there is no file.

In Mexican tax practice this is called materiality (materialidad): the ability to prove that the transaction supported by an invoice really took place on the terms the invoice describes. Since January 2026 the requirement has an express basis in the Federal Tax Code (Código Fiscal de la Federación, or CFF), and it remains a priority for the authority: on October 8, 2026, the SAT’s head of legal affairs told the Finance Committee of Mexico’s Chamber of Deputies that companies with the lowest tax payments show use of up to 10% false invoices [10]. This article explains what changed, what Mexican courts are requiring and how to move from scattered documents to a transaction-level file.

What materiality means and why the CFDI is not enough

Mexican law contains no single definition of “materiality.” The concept is built from several rules. To deduct an expense for corporate income tax (Impuesto sobre la Renta, or ISR), the expense must, among other requirements, be strictly necessary for the business and be supported by a tax invoice (Income Tax Law, Article 27, sections I and III) [5]. To credit value added tax (Impuesto al Valor Agregado, or IVA), the tax must relate to strictly necessary goods or services and be shown separately on the invoice (VAT Law, Article 5, sections I and II) [6].

In Mexico every invoice is an electronic document called a CFDI (Comprobante Fiscal Digital por Internet), certified by an authorized provider and reported to the SAT. A CFDI is a formal requirement, not proof that the transaction happened. In 2019 the Second Chamber of Mexico’s Supreme Court issued binding precedent holding that, during an audit, the SAT may verify whether the transactions recorded in a taxpayer’s books actually took place and, if the taxpayer cannot prove it, deny any evidentiary value to the invoices, without first using the Article 69-B procedure [4].

Materiality should not be confused with a related concept:

A transaction can be real and still be challenged for lack of business purpose; we cover that standard in Business Purpose in Mexico: The Standard That Can Invalidate Your Transactions Even If They Are Legal. This article focuses on proving that the transaction exists.

What changed in the Federal Tax Code in 2026, and what did not

The CFF amendments published in Mexico’s Official Gazette (Diario Oficial de la Federación, or DOF) on November 7, 2025, and in force since January 1, 2026, introduced several relevant changes [1]:

• An express invoice requirement. Article 29-A, section IX, requires every invoice to support existing, genuine transactions or real legal acts. Invoices that fail this requirement “are deemed false for purposes of this Code.”
• A fast-track visit to the issuer. Article 42, section V(g), and new Article 49 Bis allow on-site visits to verify whether an issuer’s invoices support real transactions. The visit order suspends the issuer’s ability to invoice, and the procedure must conclude within 24 business days.
• Consequences for the recipient. If the issuer is found to have issued false invoices, its name and taxpayer ID are published on the SAT website and in the DOF. Companies that used those invoices for tax purposes have 30 calendar days from the DOF publication to file amended returns. If they do not, the SAT will temporarily restrict their digital seal certificate (certificado de sello digital, or CSD), the credential every Mexican company needs to issue invoices, until the situation is cured through the clarification process provided in the same Article 17-H Bis (CFF arts. 49 Bis, section X, and 17-H Bis, section XIV) [2]. This mechanism is already in use: the SAT published the first issuers in the DOF on July 10, 2026, and continued with new publications on August 7, 14 and 28, 2026 [9].
• Criminal exposure. Article 113 Bis now also punishes anyone who gives tax effect to false invoices, with the same two-to-nine-year prison range that applies to issuing or buying them, and provides that the offense is investigated regardless of the status of any administrative proceeding [2].

Procedures that began before 2026 are resolved under the rules in force when they started (second transitory article) [1].

The Article 69-B procedure, often called the SAT “blacklist,” did not change. When the SAT detects that a taxpayer issues invoices without having, directly or indirectly, the assets, personnel, infrastructure or material capacity to provide the services or deliver the goods, or that the taxpayer cannot be located, it presumes the transactions are nonexistent. If the presumption is confirmed, the issuer is placed on a definitive list and its invoices are deemed to have no tax effect, past or present [2][3]. Companies that used those invoices have 30 days after the list is published to prove that they actually acquired the goods or received the services, or to correct their tax position through amended returns; if they do neither, the SAT may assess the corresponding taxes in an audit [2]. The lists keep growing: on October 9, 2026, the DOF published a presumption list of 76 taxpayers and two definitive lists of 106 and 14 taxpayers [7].

In practice, a Mexican company is exposed on two fronts: a direct review of its own transactions, and the tax status of its suppliers.

What Mexican courts are saying

On September 18, 2026, Mexico’s official case-law publication (Semanario Judicial de la Federación) released six isolated precedents from a federal appellate court sitting in San Andrés Cholula, Puebla. They arose from a challenge to a tax assessment issued after a desk audit in which the authority applied the Article 69-B presumption to a company’s transactions [8]. Isolated precedents are not binding, but they show the level of proof courts expect:

• Invoices, accounting records and working papers are not, on their own, full proof of materiality.
• Generically drafted contracts (in that case, gratuitous loan-for-use agreements, or comodato, that did not specify the machinery) and employment records do not prove operating capacity if they are not linked to the invoiced transactions or if headcount is inconsistent with the invoiced volume.
• Evidence is weighed under rules of logic and experience; to rebut the presumption, the taxpayer’s account must be the more probable one and the body of evidence must be complete in context.
• If each piece of evidence is rejected individually, it cannot be rescued through a joint assessment.

Other precedents are more favorable to taxpayers. A Mexico City appellate court held in 2023 that the standard of proof must be objective and reasonable for the type of transaction, and another held in 2024 that a non-complex service does not necessarily require a written contract with a legally certain date (fecha cierta), since a service order, the accounting entry, the invoice and the payment can be enough [8]. The practical conclusion is the same: evidence should be proportionate to the transaction and consistent across documents.

Risk by type of transaction in a group

Not every transaction needs the same level of support. A reasonable way to prioritize is to combine amount, nature of the transaction and counterparty profile.

Charges from a foreign parent company to its Mexican subsidiary raise additional questions and will be covered in a separate article.

The chain of evidence: contract, deliverable, payment and accounting entry

Proof is strongest when each link confirms the others. A short, consistent file carries more weight than a thick one with documents that do not match.

Business need and contract

Before the contract comes the business reason: who requested the service, for which area and for what purpose. For material transactions, the contract should describe the scope in enough detail, the price or how it is calculated, the term and the expected deliverables. A master agreement with a generic scope (“administrative services”) adds little unless it is supported by specific orders or schedules, and a contract alone does not prove that the service was rendered.

Deliverable

This is the link most often missing. For services: reports, databases, code, minutes, presentations, emails with results. For goods: delivery notes, warehouse receipts, transport documents. What matters is that they are dated and can be tied to the invoiced period and concept.

Payment

The bank transfer should match the CFDI in amount, payee and a reasonable date. Payments to third parties other than the supplier, informal netting and unexplained split payments raise questions.

Accounting entry

The journal entry should identify the transaction and its support. In groups, intercompany balances must reconcile in both entities: if one records service income and the other records a loan, the problem is no longer documentation but consistency.

One important limit: the file is built from evidence that exists. Backdating contracts, reports or minutes is not documentation; it creates additional risk, including criminal exposure. When contemporaneous evidence is missing, the right approach is to gather what does exist, explain the gaps and assess the consequences with an adviser.

From scattered documents to a transaction-level file

1. Select the sample. The twenty or thirty largest or riskiest transactions of the year, including recurring intercompany charges.
2. Define the minimum file by transaction type. A consulting service is not documented the same way as an inventory purchase.
3. Compare what exists with what is required. The output is a gap matrix, not a legal opinion.
4. Assign owners and dates. Each gap belongs to a function: procurement, legal, treasury, accounting or the business unit that used the service.
5. Build the control into the payment process. If treasury does not release material payments without a current contract and evidence of the deliverable, there is nothing to reconstruct later.
6. Monitor suppliers. Periodically check the Article 69-B and Article 49 Bis lists and the tax compliance opinion (opinión de cumplimiento) of key suppliers.

An example of the matrix format:

Hypothetical case

Illustrative example; it does not describe a client or a real case.

A foreign-owned group has three Mexican entities: a shared-services company in Mexico City, a manufacturer in Puebla and a distributor in Guadalajara. The shared-services company charges the manufacturer MXN 800,000 per month plus VAT for “administrative and management services.” Over the year, the charge totals MXN 9,600,000 plus MXN 1,536,000 of VAT.

The file shows that the contract exists and that invoices and transfers match, but there are no service reports, the allocation between the manufacturer and the distributor is undocumented, and several months were settled by netting balances without a written agreement.

If, in an audit, the manufacturer cannot prove that it received the services, and assuming it has enough taxable profit to absorb the deduction, the starting exposure would be:

The VAT is lost together with the deduction because, for crediting purposes, the VAT Law treats as strictly necessary only expenses that are deductible for income tax (art. 5, section I) [6]. The corporate income tax rate in Mexico is 30% (Income Tax Law, art. 9) [5].

Because the shared-services company has already reported the income and charged the VAT, the group could end up paying tax on both sides of the same transaction. The reasonable response is not to manufacture reports, but to gather existing evidence (emails, minutes, internal systems), formalize a service schedule and an allocation key going forward, and document the netting arrangements.

Transaction file checklist

• ☐Internal request or business justification for the transaction
• ☐Contract or order with scope, price, term and specific deliverables
• ☐Evidence of the supplier’s capacity to provide the service or deliver the goods
• ☐Dated deliverables tied to the invoiced period
• ☐CFDI with a description consistent with the contract and the deliverable
• ☐Payment to the same supplier, for the CFDI amount, from the company’s own account
• ☐Journal entry referencing the supporting documents
• ☐For intercompany transactions: balances reconciled in both entities
• ☐Supplier checked against the Article 69-B and Article 49 Bis lists
• ☐Person responsible for keeping the file and its location

Frequently asked questions

What should we do if a supplier appears on the Article 69-B list or in an Article 49 Bis publication?

Identify immediately which of that supplier’s invoices were deducted or credited and gather the evidence for those transactions. The deadlines differ: after a definitive Article 69-B list, there are 30 days from publication to prove the transaction or correct; under Article 49 Bis, there are 30 calendar days from the DOF publication to file amended returns. A presumption list is not yet final, but it is a signal to review the file.

Does a transfer pricing study prove the materiality of intercompany services?

Not on its own. The study addresses whether the price is at arm’s length; materiality requires showing that the service existed and benefited the entity that paid for it.

Can we complete the file now for transactions from prior years?

You can gather and organize evidence that already exists. What should not be done is to create documents dated earlier than when they were actually prepared.

Does this affect the parent company in its home country?

This article addresses Mexican tax consequences only. How a Mexican adjustment is treated in the parent’s jurisdiction, for example for foreign tax credits or transfer pricing, should be reviewed with an adviser qualified in that country.

A review of your highest-risk transactions

If your Mexican entities have intercompany services, consulting or material subcontracting, the first step is knowing where the evidence is and what is missing. Tax Art can review a sample of your highest-risk transactions and deliver, within the agreed scope, a transaction-level gap matrix with owners, a risk map by transaction type and control recommendations for your procurement and payment process.

Request a review of your highest-risk transaction files

Learn more about our Tax Counseling team. If you have already received a communication from the SAT, our guide to the SAT invitation letter and how to respond may also help.

This article is for information only and reflects the rules reviewed as of October 20, 2026. It does not replace an analysis of each company’s facts and documents.