Mr Zammit qualified as a Certified Public Accountant (CPA) from the University of Malta in 1985 after reading for a BA (Hons) degree in Accountancy.
During his early qualification years he worked in the industry. Later, he joined Joseph Tabone & Co (now KPMG) where he was appointed as tax consultant managing the firm's tax department.
For the last 27 years, Mr. Zammit has been in public practice, specializing in the field of taxation. He has delivered lectures to accountancy students studying for the ACCA qualification and addressed various conferences abroad.
He was a Member on Council of the Malta Institute of Accountants, for which he was representative on the Fêdêration des Experts Comptables Europêêns (FEE) Direct Taxation Working Group during 2004/2005.
Fellow member of The Malta Institute of Accountants (MIA) and of the Malta Institute of Taxation (MIT) and a member of the Institute of Financial Service Practitioners (IFSP)
Served as Assistant to the Magistrate sitting on the Administrative Review Tribunal (Income Tax) between 2011 and 2013