The ITAA is a nonprofit educational organization with members in over 65 countries whose purpose is to advance the theory, methods and principles of transactional analysis.
The professional body that sets standards of competence and ethical practice for qualified and training Transactional Analysts in all TA fields in the UK.
From Wikipedia, the free encyclopedia offering an extensive view of TA and includes links and a discussion forum
British Association for Counselling and Psychotherapy
The professional body for Counselling and Psychotherapy in Scotland