Associate Justice Catherine Triunfante Manahan

Associate Justice of the Court of Tax Appeals, Hon. Catherine Triunfante Manahan, before joining the CTA, was the Chief Legislative Officer of Senator Aquilino “Koko” Pimentel III, the President of the Senate of the Philippines. She was a tax lawyer for more than 30 years at the law offices of Romulo Mabanta Buenaventura Sayoc & De Los Angeles as well as Castillo Laman Tan & Pantaleon, interspersed with legal and corporate work at various private companies such as Isla Lipana & Co., Petron Corporation, Caltex (Philippines), Inc., Armon Realty, Inc., and government agencies like the Department of Finance, Department of Labor & Employment, Bureau of Internal Revenue (BIR) and the University of the Philippines Law Center. She was consultant to the Office of the Chairman of the Securities and Exchange Commission (SEC) to set up the SEC Internal Audit Office. She was a part-time faculty member at the UP College of Law, De La Salle University and Saint Scholastica’s College, Manila.

Justice Manahan is a graduate of the UP College of Law. She finished her AB Political Science, magna cum laude, at UP College of Arts and Sciences, Masters in Business Administration at the Graduate School of the Ateneo de Manila University and earned some units in the Doctorate Program in Public Administration of the UP National College of Public Administration and Governance (NCPAG).

She was an active member of the Tax Management Association of the Philippines (TMAP) where she last held the position of President as well as the Committee on Taxation of the Philippine Chamber of Commerce and Industry. She was also the Vice President for Legislative Affairs and Executive Director of the Legal Aid Program of the UP Women Lawyers’ Circle, Inc. (WILOCI). After her stint as TMAP President, she was appointed by the BIR as member of the Revenue National Accreditation Board that evaluates and certifies the Tax Agent Practitioners (TAP) at the BIR.

Justice Manahan authored 8 books entitled "Know Your Benefits" in 2013, "The Basics of Tax Compliance" in 2015, "TRAIN Law vs. NIRC" in 2018, "Taxpayer's Guide" in 2019, "A Concise Guide to Socioeconomic Benefits" in 2020, "2021 Updates on the 2005 Revised Rules of the Court of Tax Appeals" in 2021, "CREATE Act Amends NIRC" in 2021, and "Basic Taxation Law" in 2023 as co-authored with Atty. Tanya Renee F. Rosales in addition to the various tax articles that she published in the Business World "Taxwise or Otherwise" weekly column for almost 7 years.

Justice Manahan is married to Mr. Emiliano Martinez Manahan, Jr. with whom she has four (4) children and 2 grandchildren. She and her spouse are active members of the Couples for Christ, Inc., Saint Thomas More ministry.