Ritch, Mueller y Nicolau, S.C.

Ritch, Mueller y Nicolau, S.C. is a strong choice for handling high-end transactions across the financial, energy, and real estate sectors. The team is known for structuring complex tax strategies for M&A, private equity funds and energy projects, with recent standout work including tax negotiations in Mexico Infrastructure Partners’ $6.2bn acquisition of Iberdrola’s power assets. Tax controversy is another pillar of the practice, with the group offering end-to-end support in contentious matters, including managing tax contingencies, negotiating VAT refunds, and representing clients in audits. Oscar López Velarde is the practice head with seasoned experience in administrative appeals, mediation procedures, and corporate tax matters. The expertise of the team was strengthened by the arrival of Alejandro Santoyo in August 2024, a highly regarded tax adviser, particularly in the financial industry. The practice is praised for being ‘full of young, technical talent’, with junior partners Santiago Llano Zapatero and Juan José Paullada regularly managing complex tax issues. Llano recently led the tax analysis for América Móvil’s bond issuance in Mexico and the US, while Paullada handles an array of administrative and judicial proceedings against both state and federal authorities. Since publication, the practice has been further strengthened by the promotion of Diego Guerrero Segura to the partnership; however, Santoyo has left the firm, with both developments effective as of January 2026.