Atty. Tan is the former Chairperson of the Commission on Audit, Undersecretary of Finance and Commissioner of the Presidential Commission on Good Government. She is currently a Trustee of the International Budget Partnership, an international NGO based in Washington DC, USA. She is an Independent Director of the Asia United Bank, a director of several Philippine corporations, a tax consultant and legal adviser of some private clients, and an accredited Arbitrator of the Construction Industry Arbitration Commission, Philippines and Philippine Dispute Resolution Center, Inc, Philippines.
Atty. Tan served as Chairman of the United Nations Independent Audit Advisory Committee, the first Filipino to have been elected to this 5-member Committee. She is also a professor at the University of the Philippines for Mandatory Continuing Legal Education.
Backed by four decades of professional work in the Philippines and abroad as private law and accounting practitioner, government official, arbitrator and international consultant, she is an expert in the fields of legal, finance, audit, governance, dispute resolution and administration.
She graduated from the University of the Philippines in 1977 with a degree in Bachelor of Science in Business Administration and Accountancy and in 1981 with Bachelor of Laws. In 1987, she obtained her Master of Laws (Tax) from the New York University.