If you earn income from overseas you are not required to pay income tax in Thailand. However, members of the Thai Elite can voluntarily pay income tax in Thailand and obtain a TIN.
"Baan Smile is a wonderful service for anyone who wants assistance navigating the Thai immigration system. They offer a wide variety of services to help expats who move to Thailand. They helped us with visas and finding an apartment. The staff responded to e-mails and texts quickly and were always very friendly. I highly recommend Baan Smile."