The GAA is a legal requirement of the Canada Border Services Agency (CBSA). In the absence of an original stored by the CBSA, your service provider cannot legally act as a broker and/or remove your goods at the border. Livingstons GAA is an easy to complete and simple form, with instructions to complete it exactly. If you`ve found your agent and are ready to move your goods, download your GAA today and sign it! Are you looking for a customs brokerage service provider? Once you have found your broker partner, you must establish a General Agency Agreement (GAA) with them.