This chapter presents an analysis on the use of free trade areas (FTA) in Thailand between 2006 and 2015 in order to shed light on the ongoing negotiations of the regional comprehensive economic partnership. It examines the official records of preferential trade for Thai firms. One of the government mandates was to sign as many FTAs as possible to secure preferential market access. The government initiated 15 FTAs during the Thaksin administration period. To illustrate the use of FTAs in Thailand, the records of the certificate of origin (c/o) was analysed. By 2015, China had become the most important non-Association of Southeast Asian Nations FTA partner in terms of the c/o records. The key finding is that while c/o records significantly increased over the period in consideration, their value remained less than one-third of total trade. The constitutional amendment had a significant impact on FTAs, and the government became much less active in initiating bilateral FTAs.