The Communications Authority of Thailand (CAT) was established on 25th February 1977 as a state-owned enterprise in accordance with the Communications Authority of Thailand Act 1976. Since her establishment, all aspects of postal operations including service provisions previously undertaken by the Post and Telegraph Department were transferred to the CAT and she has been responsible for the development of the postal service ever since. During the early days, the office of the CAT was at the Central Post Office and was later moved to Chaeng Watthana Road. The CAT had developed postal infrastructure and her operating system constantly and become one the leading state-owned enterprise in the Kingdom, renowned for her capability and service quality that had continually been kept up to the international standards.