Experience
Guillermo has more than twenty years of experience in tax planning, including taxation of corporate restructuring transactions, mergers, acquisitions, and general tax advice, especially for business and multinational groups with operations in Mexico where he provides advice to achieve fiscal efficiency and provide assistance in developing tax policies for ongoing operations.
His experience extends to transfer pricing, including the legal analysis of the implementation of policies, documentation and elaboration of economic studies and defense files to protect companies against potential tax investigations. Guillermo has represented different industries before the Mexican Judiciary through constitutional (“amparo”) proceedings to contest the creation or amendments of tax laws that produce relevant economic negative effects, achieving tax refunds and the protection to future payments.
He has also assisted multinational companies in complex cross-border tax litigation, in transfer pricing adjustments, cost-sharing arrangements, multinational restructures, and potential re-characterization of intercompany payments being able to successfully defend cases in the investigation stage or to reduce potential liabilities before contesting deficiencies before the Federal Tax Court.
Guillermo is a member of the firm’s Energy Industry Group, a group that includes practitioners of different law practice areas specialized in advising clients of the energy sector. Within the Energy Task Force, Guillermo specializes in tax laws affecting the energy sector. Prior to joining Sánchez Devanny, Guillermo was a partner at an international law firm where he was responsible of the tax litigation group, nationwide and lead tax counsel in different M&A transactions. He was named as “The National Expert” for his participation in the article Transfer Pricing 2018 included in the edition Getting the Deal Through, “Expert Panel 2018” by The Law Reviews for his participation in the Mexico Chapter of The Oil & Gas Law Review and “Contributor” by Chambers and Partners for his participation in the Global Practice Guides – Tax Controversy 2021. He is fluent in English and Spanish.
Special Studies in International Taxation. Georgetown University Law Center, Washington, D.C.,
USA (2010).
Special Studies in Transfer Pricing. Universidad Anahuac / Universidad Cantábrica, México, D.F.,
México (2010).
Postgraduate Studies in Tax Law. Escuela Libre de Derecho, México, D.F., México (2004).
Law Degree. Universidad Iberoamericana, México, D.F., México (2000)
LANGUAGES: Spanish, English.
"He always supports us and is proactive, sending us relevant information for our business.” – Chambers Latin America 2025
“We are very happy with the service given by Guillermo Villaseñor Tadeo, who is an excellent lawyer.” – Chambers Latin America 2025
“I can always rely on Sánchez DeVanny Eseverri. The team has strong technical skills to handle complex matters and is organised in the most efficient way.” - Chambers Latin America 2025
“Sánchez DeVanny Eseverri's team is up to date on tax issues and supports us with complex issues. The lawyers provide us with legal solutions to mitigate risks and make the best decisions.” - Chambers Latin America 2025
“Guillermo Villaseñor Tadeo is a very technical and professional lawyer, who is always attentive and available”. - Chambers Global 2024
