Hi I reside in Thailand as a dependent on my wife’s employment visa/work permit and do not have any Thailand-based employment or investment income. I want to confirm that in light of the above, I am NOT required to have a Thailand TIN or file a Thai tax return, as my wife does.

If you do not have any assessable income (Thai income or overseas income that is remitted to Thailand) then you don’t need a Tax ID number. Your spouse can use your passport number on her tax return.

You are not required to have a Thai tax ID number or file if you have no income (your wife can file as a joint married with a spouse with no income)