What a Tax Attorney Does and When to Hire One

Quick answer: the tax attorney defends companies and individuals before the tax authorities and organizes the tax burden before it turns into litigation. The work spans four areas: administrative defense against assessments, judicial defense in tax enforcement proceedings and in claims of its own, preventive advisory work on the structure of the business, and regularization or recovery of credits.

The scene has repeated itself for two decades. A mid-sized company receives, in its e-CAC electronic mailbox (the Brazilian Federal Revenue Service's official electronic communications channel), an auto de infração (tax assessment notice) for several million reais relating to an audited period that already seemed closed. The accountant understands the assessment, but not the litigation. The partner understands the business, but not the deadline that has already started to run. Between becoming aware of the notice and making a decision, days go by that cost dearly.

What a tax attorney does is occupy that space. It is not the person who calculates the tax, which is the accountant's role. It is the person who reads the assessment to find where it is weak, decides whether the path is administrative or judicial, sizes up the partner's personal asset risk and, when the matter has not yet become a proceeding, redesigns the operation so that the liability never forms.

The four areas of practice

Tax law practice is often portrayed as a synonym for "fighting with the tax authorities." That is one part of it. The real distribution of the work breaks down like this:

The right decision is almost never one of those columns in isolation. A R$ 8 million liability may warrant a challenge on one part, a settlement on another and an annulment action on a third. Separating what is to be disputed from what is to be negotiated is the tax attorney's first technical deliverable.

Scenario 1: a high-value assessment

Significant assessments rarely arise from gross error. They arise from a difference in interpretation: excluding one tax from the calculation base of another, taking a credit, the tax classification of goods, disallowance of a deductible expense. The company acted on a legal basis and the tax authority saw it differently.

The work begins with a cold reading of the audit report: which fact was described, which legal provision was pointed to as violated, whether the calculation base and the penalty match the conduct charged, and whether part of the period has already been reached by decadência (the lapse of the authorities' right to assess) as provided in the National Tax Code (Law 5.172/1966). Finding a defect in the stated grounds or an error in the calculation is worth more than any sophisticated argument presented too late.

There is an effect specific to federal administrative litigation that factors into the analysis. Law 14.689/2023 established that, when the administrative proceeding is resolved in favor of the National Treasury by the voto de qualidade (the casting vote of the presiding member in a tie) at CARF, the penalties levied on the credit are excluded and the criminal tax referral is cancelled. That changes the math of continuing to litigate in the administrative sphere in tie cases.

Scenario 2: a tax enforcement proceeding against the company

When the debt is entered on the dívida ativa, collection becomes governed by Law 6.830/1980, the Tax Enforcement Law. The point that surprises business owners is the order of things: embargos à execução, which is the full defense, are only admitted after the judgment is secured, with a 30-day deadline counted from service of the attachment, from the cash deposit, or from the filing of proof of the bank guarantee or guarantee insurance.

There is a narrower route that requires no security. Under Precedent 393 of the STJ (Superior Court of Justice), the exceção de pré-executividade is admissible in a tax enforcement proceeding as to matters the court may raise on its own motion that do not require the taking of evidence: completed limitation period, evident lack of standing, an instrument lacking the requirements of certainty and liquidity. A classic mistake is to insist on it in a matter that requires evidence.

Time also plays a role. Article 40 of Law 6.830/1980 governs the stay of the proceeding when no attachable assets are located, and Precedent 314 of the STJ settled that, in that situation, the proceeding is stayed for one year, after which the five-year prescrição intercorrente (limitation period running during the proceeding itself) begins. An old, dormant enforcement proceeding deserves examination before any payment proposal.

There is also the risk that reaches the partner. Precedent 430 of the STJ established that a company's failure to pay a tax obligation does not, in itself, give rise to joint liability of the managing partner. Precedent 435, in turn, presumes irregularly dissolved a company that ceases to operate at its registered tax domicile without notifying the competent authorities, which legitimizes redirecting the enforcement proceeding. Between one precedent and the other it is decided whether personal assets enter the dispute, and winding up a company in a disorganized way is one of the costliest mistakes we see.

Scenario 3: the tax burden eating into the margin

This is the scenario where the tax attorney delivers the most and shows up the least, because nothing happens. A retail chain with revenue in the tens of millions operating under the wrong tax regime, a manufacturer that does not take credits it is entitled to, a group with everything concentrated in a single legal entity. Money is leaving because of an architectural decision, not because of an assessment.

Advisory work starts from the actual tax calculations of recent fiscal years, cross-references them with the business model and tests alternatives within the law. This is legitimate planejamento tributário (tax planning), with a demonstrable business purpose, because structure without substance is a future liability with interest. The transition to the Tax Reform, which began with Constitutional Amendment 132/2023, has made this examination more urgent.

Scenario 4: corporate and asset reorganization

Succession in a family business, a new partner coming in, sale of an equity interest, formation of a holding company, transfer of real estate within the same group. Every significant asset decision carries a tax cost that varies according to the form chosen, the timing and the documentation: the same transaction may be neutral or costly depending on how it was structured.

Here the tax attorney works alongside corporate and succession counsel, and the question is always the same: what is the tax exposure of this structure today, and what would it be in an audit five years from now. Families with assets across multiple classes often discover that a design made a decade ago does not withstand current rules.

And for those who came here thinking about a career

A quick note for the student or the attorney in transition. A career in tax law requires a solid foundation in Constitutional Tax Law and in the National Tax Code, constant reading of STJ and STF (Federal Supreme Court) case law, real fluency in accounting and a willingness to handle long-running litigation. Experience at a firm teaches more than any single course. The rest of this text is written for those who need to hire.

What to assess before hiring

Anyone with a seven-figure liability at stake does not hire on price or on promises. They hire on fit, and the profile of practice of the advogado tributarista (tax attorney) matters more than the size of the structure. Five points account for nearly the entire decision:

1. Practice in both spheres. A significant liability usually travels through the administrative and the judicial spheres, and the strategy in the first conditions the second. 2. Diagnosis before proposal. Someone who asks for the documents, examines the assessment, the certificate of registered debt and the stage of the proceeding, and only then says what is possible. Someone who states the outcome before reading the case file is selling, not analyzing. 3. Honesty about the odds. Hearing "here the dispute is not worth the time, the path is a settlement" is worth more than hearing what you want to hear. 4. Dialogue with your accountant. A tax attorney isolated from the company's accountant loses essential information. The good dynamic is collaborative, with clear roles. 5. Realistic horizon. Tax enforcement proceedings and administrative litigation are measured in years. Continuity of the team matters as much as individual talent.

No serious professional guarantees a result, and the Brazilian Bar Association prohibits doing so. What should be demanded is clarity about the possible scenarios and about what depends on the court, not on the firm.

When negotiating is the technical decision

Law 13.988/2020 governs the transação tributária, and the Office of the Attorney General of the National Treasury has graded the benefits according to the debtor's ability to pay, classified into brackets. The legal work here is not drafting the enrollment, which is operational. It is deciding what goes into the negotiation and what stays out, and checking whether part of the debt is already time-barred before acknowledging it.

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Informational content; it does not replace individual legal advice. Each case has particularities that require specific analysis.

Dr. Wendel Ferreira Lopes — Attorney, OAB/MG nº 18.881. Founding partner of WF Advogados, practicing in Tax, Banking and Estate/Succession Law since 1999. Uberlândia/MG, Brazil.

Frequently Asked Questions

What does a tax attorney do?

Defends companies and individuals in tax assessments, tax enforcement proceedings and other disputes with the tax authorities, in the administrative and judicial spheres, and provides preventive advice on tax regime, credits and corporate structure.

What is the difference between the tax attorney and the accountant?

The accountant calculates taxes, complies with ancillary obligations and maintains the books. The tax attorney works on the interpretation of the rule, on the defense in litigation and on the legal structuring of transactions. They are complementary roles.

When should I hire a tax attorney?

Upon receiving a tax assessment notice or service of process in a tax enforcement proceeding, upon identifying a tax burden disproportionate to the activity, before a corporate reorganization or sale of an equity interest, and before enrolling in an installment plan or settlement of significant value.

Can I defend myself against a tax assessment without an attorney?

The administrative challenge may be filed by the taxpayer directly, but technical defense carries weight when the dispute depends on case law and on the validity of the assessment. In the judicial sphere, representation by an attorney is mandatory.

Is it possible to dispute a tax enforcement proceeding without securing the judgment?

Yes, in limited situations. Precedent 393 of the STJ allows the exceção de pré-executividade as to matters the court may raise on its own motion that do not require the production of evidence. For the full defense, embargos require security.

Is the partner liable with personal assets for the company's tax debts?

Not automatically. Under Precedent 430 of the STJ, mere non-payment does not give rise to liability of the managing partner. Redirection depends on specific situations, among them the irregular dissolution addressed in Precedent 435.

Do tax debts become time-barred?

Yes. The National Tax Code sets a five-year limitation period for collecting a definitively assessed credit, and Precedent 314 of the STJ addresses the limitation period running during an enforcement proceeding stayed for lack of attachable assets.

Is it better to dispute or to negotiate a tax liability?

It depends on the strength of the legal argument, the amount, the stage of the proceeding and the impact of time on cash flow. Liabilities often accommodate both solutions in distinct parts, and that separation is a technical decision, not a preference.