An Associate Justice of the Court of Tax Appeals, Justice Catherine Triunfante Manahan was formerly the Chief Legislative Officer of Senator Aquilino “Koko” Pimentel III, the President of the Senate of the Philippines before joining the CTA.

She has over 30 years of experience within the field of law, while dealing with corporate and tax works in various private companies as well as government agencies. She was also a part-time faculty member in different universities such as UP College of Law, De La Salle University
& St. Scholastica’s College.

She wrote several books on taxation, the most known being Amend Acts NIRC, Train Law vs. NIRC, and Taxpayer’s Guide.