Mattos Filho‘s Brasília tax practice operates on two key fronts: high-stakes litigation and strategic public policy engagement. On the contentious side, the team remains active before the Superior Court of Justice, the Supreme Court, and CARF. In the policy arena, the practice is a key participant in legislative discussions with Congress and executive bodies. This dual capability makes the firm a sought-after adviser for clients operating in a variety of sectors. The team’s expertise is embodied by its key practitioner Ariane Costa Guimaraes, a tax litigation specialist noted for representing corporate interests before the National Congress and key government ministries. Further adding to the team is associate Pedro Henrique de Castro Motta, who brings deep knowledge of judicial tax litigation.
Legal 500 Editorial commentary
Testimonials
Collated independently by Legal 500 research team.
‘The firm has excellent capacity to operate in administrative and higher courts, especially in Brasília. As it is a full-service firm, the involvement of different areas and practices greatly contributes to the deliveries and solutions presented to clients.’
‘Ariana Guimarães actively participates in discussions and interactions with clients, with great availability. Her vision on case law and positions of higher courts is notable.’
- 'Technical quality, oral advocacy skills, and relationships with the higher courts.'
- 'High technical quality of its lawyers and the ability to offer a complete service (“full-service”), covering practically all the legal needs of large companies. Despite its range, the firm has highly specialised teams within each practice area. The firm seeks to position itself as a strategic partner to its clients, aiming to understand their businesses in depth in order to offer legal solutions aligned with their goals.'
- 'Mattos Filho is often involved in discussions on new legislation and relevant topics for the business environment in Brazil. Its partners are frequently invited to give their opinions and actively participate in professional associations and debate forums, positioning the firm as a thought leader. I particularly value the work of Ariane Guimarães.'
- 'The firm is a benchmark in handling complex tax matters, consistently presenting creative and reliable approaches for both advisory and contentious issues. Their strategic performance in significant cases is a strong differentiator.'
Key clients
- Cassol
- Banco Santander
- Instituto para Desenvolvimento do Varejo
- Magazine Luiza
- General Motors do Brasil LTDA
- Qualicorp Corretora de Seguros S.A.
- DIMED S.A. - Distribuidora de Medicamentos
- Companhia Brasileira de Distribuição
- Prosegur Brasil S.A Transportadora de Valores e Segurança
Work highlights
Represents Banco Santander and FEBRABAN (Brazilian Federation of Banks) in the most relevant tax lawsuit for the financial sector in the Supreme Court.
Represents Qualicorp Corretora de Seguros S.A. before the Superior Court of Justice in a case which discusses the legal classification of Stock Option Plans (SOP), identifying whether they are remuneration for word or a commercial contract.
Acted directly on Extraordinary Appeal No. 949,297 at the Supreme Federal Court (STF), which discussed the effects of binding decisions issued by the Supreme Court on res judicata previously formed in individual tax matters.
Lawyers
Leading partners
The strongest partners in their field, leading on market-leading deals and endorsed by peers and clients alike.
Practice head
Ariane Guimarães
Other key lawyers
Pedro Henrique de Castro Motta; Lucas Ianagui de Carvalho Leite