The ten nation members of the Association of Southeast Asian Nations (ASEAN) utilize English as the official working language for the organization. This study focused on the nation of Thailand to examine the assessed level of English proficiency of its workforce in relation to its ability to interact within ASEAN’s economic community (AEC). This is the first academic study to utilize a sample population consisting of human resources personnel from the top 100 private companies in Thailand who are in charge of employee training for learning English. Self-administered questionnaires were used to obtain self-assessments on the issues of level of English proficiency, language training, resource allocation for communication preparedness in AEC, and overall perceptions of the importance of mastering English within their respective companies. The results indicate that the acquisition of English as an economic lingua franca was considered important regardless of the demographic factors of the company examined. A majority of the respondents expressed the belief that their businesses had provided adequate resource allocation for English preparedness and a majority also indicated that their respective workforces possessed adequate English skills. However, a majority also expressed assessments that the employees in their companies did not find it easy to learn English and that Thais in general, and their employees in particular, did not like learning the language.