Alonso leads the firm´s tax practice. He is a partner at BLP Abogados since 2009. Previous to this he was the tax partner in charge for Central America at KPMG Central America, San José, Costa Rica. He was also a member of the International Corporate Tax, Tax Mergers & Acquisitions, and Latin America Tax Group. From 1994 up to 2000 he has the correspondent for Backer & McKenzie on tax matters for Costa Rica.

Alonso is a graduate from Harvard University Law School, where he obtained the Master of Laws Degree. He is also a graduate from the International Tax Program from the Harvard Law School and Kennedy School of Government.

Alonso is an active member of the Inter-American Bar Association, an International Associate of the American (U.S.) Bar Association, International Fiscal Association and the Tax Division of the American Bar Association.