Buying a Business in Mexico: Tax Findings That Can Affect the Purchase Price
When a foreign buyer acquires a Mexican company, the target’s tax history comes with it. The Mexican Tax Administration Service
A merger, a spin-off or a transfer of shares within a group usually reaches the board as a finished project: the structure, the timetable and the legal documents. What is often missing is the file that explains why that structure was chosen and what economic benefit is expected from it. Years later, that file is what allows the group to show the business purpose of a restructuring to the SAT, Mexico’s federal tax authority.
We have already explained what business purpose means in Mexico and when the SAT applies it. This guide takes the next step: what the board or shareholders should have on record before approving a restructuring of Mexican companies, and which additional rules apply to each type of transaction. Corporate approvals in the parent’s country follow their own rules; this guide covers the Mexican tax side.
Executive summary
Article 5-A of the CFF treats as a tax benefit any reduction, elimination or temporary deferral of a tax, and considers that there is a reasonably expected economic benefit when a transaction seeks to generate income, reduce costs, increase the value of assets or improve market position, among other cases. That benefit is measured using contemporaneous information about the transaction, including the projected benefit, to the extent it is supported and reasonable.
The practical consequence is simple: if the information explaining the restructuring did not exist when the decision was made, it is not contemporaneous. The minutes, models and analyses presented to approve the transaction are the best evidence available.
The rule is not applied automatically. The authority must raise it during an audit, give the taxpayer the legal period to present evidence and first obtain a favorable opinion from a committee of officials from the Ministry of Finance and the SAT. Its effects are limited to determining taxes, accessories and penalties, without prejudice to any criminal investigation.
Mexico’s Federal Court of Administrative Justice has also held that the absence of a business purpose may be one of the elements, though not the only one, for denying that a transaction took place, and that the taxpayer then bears the burden of proving it. For how to build that supporting file, see our guide on tax materiality in Mexico.
The first part of the file answers two questions: what business problem the restructuring solves, and what other ways of solving it were considered.
Objectives should be concrete and measurable: eliminating duplicated administrative costs, separating a business to sell it or bring in a partner, isolating operating risks, simplifying the structure to obtain financing. An objective described only as “efficiency” or “simplification” cannot be measured later.
Alternatives matter for a specific legal reason: the authority may presume a lack of business purpose in a series of transactions when the same economic benefit could have been achieved with fewer steps and a heavier tax result. If the board compared the chosen structure with simpler options and recorded why it rejected them for business reasons, that presumption has a documented answer.
The second part quantifies the expected economic benefit, separately from the tax effect. It should include:
Mexican law uses the comparison between economic benefit and tax benefit to presume a lack of business purpose. A larger economic benefit does not guarantee that the transaction will not be challenged, but a file showing the opposite leaves it exposed.
The third part turns the analysis into a formal decision and then shows that it was carried out:
One rule has no exception: the file documents facts. If an analysis did not exist when the decision was made, it should not be created later with an earlier date. The right course is to document, with the current date, what actually happened and the evidence available, and to build the position on those facts.
| Transaction | Specific rule | Legal basis |
|---|---|---|
| Merger or spin-off | Not treated as a sale if requirements are met; if the authority finds no business purpose, it may tax it as a sale, considering relevant transactions in the five years before and after | CFF art. 14-B |
| Spin-off | Among other requirements, shareholders holding at least 51% of the voting shares must keep them for three years | CFF art. 14-B |
| Later relevant transactions | If a relevant transaction occurs within the following five years, information must be filed with the SAT | CFF arts. 14-B and 31-A |
| Transfer of shares at tax cost within the group | Requires prior SAT authorization; if the restructuring lacks a business purpose or a requirement is not met, the authorization is void and tax is due on the sale | Income Tax Law (LISR) art. 24 |
| Merger with tax losses | The surviving company may use its own pending losses only against profits from the same lines of business that generated them | LISR art. 58 |
| Restructuring that takes the company with losses out of the group | The authority may presume an improper transfer of tax losses | CFF art. 69-B Bis |
| Related-party restructurings with no payment for transferred assets, functions and risks, or that reduce operating profit by more than 20%; transactions that transfer tax losses | May be reportable schemes that advisers or taxpayers must disclose to the SAT | CFF art. 199 |
Mexico’s Congress has approved the 2027 income tax reform: on November 3, 2026, the Chamber of Deputies accepted the Senate’s changes and sent it to the Executive; it takes effect only once published in the DOF, Mexico’s Official Gazette. According to the initiative, it limits the use of tax losses for companies with income above MXN 50 million, and the exception for newly created companies does not apply to companies resulting from or surviving mergers or spin-offs carried out on or after September 8, 2026. A restructuring that includes a merger or spin-off should be reviewed against the published text.
Illustrative example; it does not describe a client or a real situation.
A foreign-owned group has three Mexican companies: a holding company in Mexico City and two manufacturers, one in Puebla and one in Guadalajara, each with its own administrative team. Management proposes merging the manufacturers.
| Alternative | Expected economic benefit (3 years) | Estimated tax effect | Board decision |
|---|---|---|---|
| A. Merge the manufacturers | MXN 24 million in savings from removing duplicated functions | Estimated deferral of MXN 3 million | Approved |
| B. Shared service center without a merger | MXN 10 million in savings; two legal structures remain | No relevant effect | Rejected: lower savings |
| C. No change | No savings | No effect | Rejected |
The file includes the savings model with its assumptions (headcount, leases, systems), the separate tax analysis, minutes recording the discussion of all three alternatives and a quarterly follow-up plan. In this example, the expected economic benefit (MXN 24 million) exceeds the tax effect (MXN 3 million), but that alone is not enough: the group must also meet the requirements of article 14-B and keep evidence that the savings were actually pursued.
| Item | What to document | Evidence | Owner |
|---|---|---|---|
| Objective | Business problem and measurable goal | Board presentation | Chief executive |
| Alternatives | Options assessed and reasons for rejecting them | Comparative analysis | Finance and legal |
| Economic benefit | Amount, horizon and method, excluding tax effects | Dated financial model | Finance |
| Tax effect | Separate estimate | Tax analysis | Tax |
| Decision | Deliberation and approval | Minutes with identified annexes | Board secretary |
| Execution | Steps taken and results measured | Agreements, notices, follow-up reports | Operations |
Before the board votes, check:
Is it enough for the restructuring to meet the legal requirements of the transaction?
Not necessarily. Meeting the requirements for a merger or spin-off is essential, but the authority may also review whether the transaction has a business purpose.
What if the restructuring has already happened and there is no file?
Gather the evidence that does exist from that time (emails, presentations, models, minutes) and document the results obtained with the current date. Do not prepare documents with earlier dates.
Does an economic benefit larger than the tax benefit remove the risk?
It reduces the risk that the presumption applies, but it does not remove it. The authority may consider other elements, and the burden of proving the transaction may fall on the taxpayer.
The best time to review business purpose is before the board votes. At Tax Art we can review the project, the requirements of the transaction under Mexican law and the decision file and, within the agreed scope, propose the alternatives and evidence matrix to accompany the approval.
Request a tax assessment of your restructuring project through our Tax Counseling team.
Request a restructuring assessment
This article is for information only and reflects the rules reviewed as of November 11, 2026. It does not replace an analysis of each transaction or advice on the rules of the parent’s country.
When a foreign buyer acquires a Mexican company, the target’s tax history comes with it. The Mexican Tax Administration Service
Many groups with several companies in Mexico centralize administration, IT, legal and management in one entity and charge the others
