There is a strategic mistake that Mexican companies of all sizes repeatedly make: believing that their corporate lawyer can resolve any legal conflict they face, including those in which the State is the counterparty. The result is usually costly: missed deadlines, poorly filed appeals, lost government contracts, and sanctions that could have been avoided. The distinction between private law and public law is not an academic technicality; it is a dividing line that determines which laws apply, in which courts litigation occurs, on what deadlines action must be taken, and, ultimately, whether your company has a viable defense.

If your company interacts with the State —as a supplier, a regulated entity, a taxpayer, or a contractor— you need to know exactly when a corporate lawyer is not enough.

What is the fundamental difference between a corporate lawyer and a public law lawyer?

Public law governs the relationships between the State —represented by the Public Administration— and individuals, as well as between the different state bodies. Private law, on the other hand, regulates relationships between individuals on equal terms.

Corporate law is an essential branch of private law that regulates the functioning of companies, covering topics such as decision-making, administration, protection of intellectual property rights, as well as financial, labor, tax, and intellectual property aspects.

The practical difference is radical: in corporate law, the parties negotiate on a relatively horizontal plane. In public law, one of the parties is the State, which acts with prerogatives of authority —that is, with powers that any individual lacks— and can impose obligations, sanctions, seizures, cancellations of permits, and even debarment without the need to go to a judge beforehand.

What situations trigger the urgent need for a public law lawyer?

When you receive a notification or resolution from SAT, IMSS, or INFONAVIT

When the tax authority notifies taxpayers of specific acts or resolutions —such as the determination of a tax liability, the denial of a tax refund, or the seizure of assets— taxpayers and third parties whose legal interest is affected have non-jurisdictional defense mechanisms at their disposal, such as the administrative appeal for revocation, and jurisdictional defense mechanisms, such as the contentious administrative trial or trial of nullity.

A corporate lawyer can draft flawless contracts, but if they do not know the fatal deadlines of the Federal Tax Code —where the deadline to file an appeal for revocation is 30 business days— or if they do not know the technical difference between an appeal for revocation and a trial of nullity before the Federal Court of Administrative Justice (TFJA), the mistake can be irreparable.

When you participate in public tenders or contracts with the government

The Public Administration cannot carry out its activities without systematic processes such as public bidding, which must be governed under the principles of opportunity, public inquiry, competition, and equality among participants, offering the best conditions to contract with the Government.

Participating in a tender under the Law on Acquisitions, Leasings, and Services of the Public Sector (LAASSP) or the Law on Public Works and Related Services (LOPSRM) involves facing public law rules at every stage: from the review of bidding guidelines and submission of proposals, to challenging a direct award that you consider illegal. A corporate lawyer who is unfamiliar with the objection petition before the Ministry of the Civil Service (SFP) and its deadline of six business days cannot effectively protect your interests in this arena.

When a license, permit, or concession is cancelled, revoked, or denied

The contentious administrative trial serves to challenge the legality of acts such as fines imposed by administrative authorities, tax liabilities determined by the SAT, bank account or asset seizures, closure of commercial establishments, and the denial of permits, licenses, or concessions.

For companies operating in regulated sectors —telecommunications, energy, transport, health, construction, food— the cancellation of a concession or the rejection of a permit can mean the end of operations. These situations are not resolved with a commercial lawyer: they require mastery of administrative law, knowledge of the trial of nullity, and, in many cases, the filing of an amparo trial with a request for provisional suspension of the act so that the company can continue operating while the merits of the case are litigated.

When the company faces administrative liability proceedings

Infractions by private parties are acts or omissions of individuals or corporate entities linked to serious administrative offenses, for which sanctioning is the responsibility of the Court of Administrative Justice. This means that a private company can be directly investigated and sanctioned under the General Law of Administrative Responsibilities (LGRA) if it is linked to acts of corruption in transactions with the public sector.

In these scenarios, the company needs a lawyer who deeply understands the procedures before the Federal Supreme Auditor (ASF) and the Ministry of the Civil Service (SFP), especially when the imputed conduct can lead to consequences for serious administrative offenses before the ASF or the SFP, which include multi-million dollar fines, debarment, and even the dissolution of the legal entity.

What areas of public law must lawyers advising companies know?

Not all public law lawyers are the same. Depending on the type of company and its interactions with the State, the most relevant specialties are:

Administrative and regulatory law

It is the core of public law applied to businesses. It covers the relationship with regulatory agencies such as COFEPRIS, SEMARNAT, PROFEPA, CRE, IFT, CNBV, and any other authority that issues permits, licenses, or concessions, or that sanctions non-compliance.

Tax law and contentious tax proceedings

Although many tax lawyers exist, the key difference lies in tax litigation: knowing not only how to structure the tax burden, but also how to defend the company against tax liabilities, SAT audits, seizures, and enforcement proceedings, using the appeal for revocation, trial of nullity before the TFJA, and the amparo trial.

Public procurement law

It involves in-depth knowledge of the LAASSP, the LOPSRM, their regulations, and the criteria of the TFJA and the SFP. It is essential for companies that bid, execute government contracts, or seek to defend themselves against terminations or penalties imposed by public entities.

Anticorruption and administrative responsibilities law

Following the implementation of the National Anticorruption System (SNA), private companies participating in government procurement are subject to direct sanctions under the LGRA. A lawyer specialized in this area understands the investigation procedures, the rights of the private party during the proceeding, and defense strategies before the Court of Administrative Justice.

Customs and foreign trade law

Importing and exporting companies constantly interact with the General Administration of Customs, which is a public authority. Administrative procedures in customs matters (PAMA), appeals for revocation, and trials of nullity arising from merchandise seizures are the exclusive domain of the public law lawyer, not the corporate lawyer.

When IS a corporate lawyer sufficient, and when is it NOT?

What risks does a company face by relying only on its corporate lawyer before the State?

The risks are concrete and quantifiable:

Loss of non-extendable legal deadlines. Contentious administrative trials proceed against definitive administrative resolutions and certain administrative acts of a general nature, in accordance with the Federal Law of Contentious Administrative Procedure. A lawyer who is unaware of these deadlines —which in many cases are just 15 or 30 business days— can leave the company without a defense.

Tacit consent to the act of authority. In administrative law, failing to challenge an act within the legal deadline is equivalent to accepting it. An unchallenged tax credit timely becomes demandable; an unappealed debarment becomes final.

Incorrect choice of defense mechanism. The appeal for revocation is filed before the same authority that issued the act or resolution affecting the legal interest of the individual. Once the authority receives the written filing, it must analyze whether it complies with formal requirements regarding the standing of the promoter, the timeliness of the submission, and other technical elements which, if omitted, will result in the dismissal of the appeal without the merits of the case being analyzed.

Impossibility of obtaining a suspension of the act. Only a lawyer experienced in amparo trials knows when and how to request the provisional suspension of an administrative act, which can be the difference between a company continuing to operate or being paralyzed for years of litigation.

Liability for costs and damages. A mistake in selecting the court or judicial path can result in the complete loss of the right to collect or demand performance. Knowing and applying these criteria is essential for every lawyer, business, or professional who enters into contracts with the public sector in Mexico.

How should a company structure its legal team when operating with the public sector?

The most efficient answer is not to replace the corporate lawyer, but to complement them. Companies with significant operations involving the State should consider the following scheme:

Corporate lawyer: Designing corporate structure, private contracts, corporate governance, intellectual property, commercial disputes between private parties.

Public law lawyer: All interactions with regulatory authorities, defense against acts of the public administration, bidding, and government contracts, administrative appeals and contentious-administrative trials, amparo trials, liability proceedings under the LGRA.

Contentious tax lawyer: SAT audits, tax liabilities, appeals for revocation, trials of nullity in tax matters, conclusive agreements before the PRODECON.

In mid-sized companies that cannot support three different specialties, the priority must be to verify that the general counsel has solid training in public and administrative law, not just in private corporate law.

Applied Public Law: The Most Frequent Critical Scenarios for Mexican Companies

Companies supplying the government

The execution of a public contract is governed entirely by rules of public law. A correct execution of public contracts requires knowing the rules on contract modifications, grounds for administrative termination, deduction and penalty procedures, and claim mechanisms before the contracting agency. None of this falls under the domain of the traditional corporate lawyer.

Companies in healthcare, energy, or telecommunications

They operate under concessions and permits that can be revoked by authorities such as COFEPRIS, CRE, or IFT. Defending against the revocation of a concession or the imposition of regulatory sanctions is the exclusive territory of public law.

Importers and exporters

All their relationships with Mexico’s Customs —declarations, valuation, tariff classification, seizures, PAMA— are of a public nature. Errors in this area are defended before the TFJA and, in extreme cases, through federal amparo trials.

Companies that have been sanctioned or debarred

Faced with a debarment resolution issued by the SFP, the company has very short deadlines to react. Debarment prevents participation in any public tender or government contract during the sanctioned period, which for many companies is equivalent to total commercial paralysis.

Public law lawyer: not a luxury, but a strategic necessity for companies operating before the State

The Mexican State is one of the most powerful economic actors in the country: it is a buyer, regulator, sanctioner, and, at times, a counterparty in legal conflicts of high technical complexity. Facing it without the right specialist is one of the most costly strategic mistakes a company can make.

The corporate lawyer is essential for structuring and protecting the business in the private world. The public law lawyer is equally essential —and often more urgent— when the State enters the scene: whether as a sanctioning authority, a terminating contractor, a revoking regulator, or an entity before which you must defend your rights within deadlines that allow no delay.

Identifying which of the two you need, and when, can be the most important legal decision your company makes.

Frequently Asked Questions

Is a tax lawyer the same as a public law lawyer?

Not exactly, although there is overlap. The tax lawyer specializes in the tax relationship between the company and treasury authorities (SAT, IMSS, INFONAVIT). The public law lawyer has a broader scope: covering tax law, but also administrative law, public procurement, regulatory law, and administrative liability proceedings. A tax lawyer with litigation training has many of the public law lawyer's skills, but not all.

At what point in a bidding cycle does the company need a public law lawyer?

Ideally, even before presenting the proposal. A public law lawyer can review the bidding guidelines to identify abusive or illegal clauses, advise on qualification requirements, prepare the technical and economic bid from a regulatory compliance perspective, accompany the evaluation process, and, if the outcome is adverse, file the objection petition before the SFP within the legal deadline of six business days. Intervening only at the end —when an adverse act has already occurred— is always more expensive and riskier.

Can an amparo trial be filed by a private company against the government?

Yes. The indirect amparo trial is one of the most powerful remedies in the Mexican legal system and is available to corporate entities (companies) when an act of authority violates their fundamental rights, such as rights to property, due process, or legal certainty. Through amparo, a company can obtain the provisional suspension of a fine, debarment, permit cancellation, or seizure while the merits of the case are being resolved.

What happens if my company does not respond to an act of authority on time?

In public law, silence can be interpreted as consent to the act. If a company does not file the appeal for revocation or the trial of nullity within the legal deadline, the administrative act becomes final and enforceable. This means the authority can proceed with the forced collection of the tax credit, bank account or asset seizures, or initiate execution proceedings without having to obtain an additional court ruling.

How can I know if my company needs a public law lawyer right now?

A rule of thumb: if your company has received any official communication from a government agency —letter, official notice, requirement, resolution, minutes— or if you are about to participate in a tender, sign a government contract, renew a license, or face a SAT audit, the time to consult a public law lawyer is now. Not after the deadlines have expired.

Is it possible for a single lawyer to handle both corporate and public law?

Theoretically yes; in practice, it is difficult to do so with the depth each specialty requires. Corporate law and public law have completely different legislation, forums, deadlines, and strategies. For a company with regulated operations or that interacts with government, the most prudent course is to have specialized advice in each area, even if on a complementary and non-permanent basis.