Can I legally do freelance remote work in Thailand with my current work permit?

The original poster inquires about the legality of engaging in part-time remote freelance work while holding a teaching work permit in Thailand. They express willingness to declare income and pay taxes. Various commenters provide insights, with some suggesting that a second company could be added to the existing work permit, while others assert that the type of work and visa conditions complicate the issue, pointing out that individuals on a different visa (DTV) may not require a work permit for certain freelance work. Confusion exists regarding the necessity of setting up a company, acquiring a new work permit, and the implications of working for clients outside Thailand.