[...] so one could potentially have to jump through all the hoops for a legal work status, yet have no taxable earnings.

I think you are mistaken. You only need a work permit if you are performing work in Thailand. Thai-sourced income is taxed in Thailand no matter where it's remitted. If you are performing the work in Thailand (physically present here) it is Thai-sourced and subject to taxation here.

What is not taxable is income that is sourced outside of Thailand such as capital gains from investments held offshore, or employment income for work carried outside of Thailand for a foreign employer.

Edited March 16, 201016 yr by kudroz

[...] so one could potentially have to jump through all the hoops for a legal work status, yet have no taxable earnings.

I think you are mistaken. You only need a work permit if you are performing work in Thailand. Thai-sourced income is taxed in Thailand no matter where it's remitted. If you are performing the work in Thailand (physically present here) it is Thai-sourced and subject to taxation here.

What is not taxable is income that is sourced outside of Thailand such as capital gains from investments held offshore, or employment income for work carried outside of Thailand for a foreign employer.

OK. I get it. I misread the regulation and thought the OP could potentially have overseas income (from self employment in Thailand) paid overseas then remit it to Thailand tax-free in a different year. What you describe makes sense, although I still think it would be difficult to prove if someone had any savings and could just say the money came from there, not investments or employment or whatever. Presumably something like employment income (for work carried outside of Thailand for a foreign employer) would be taxed at source anyway?