Where: Scope of assessable income
Source rule
non residents are taxed on all income accruing in or deriving from Thailand.
(income from ⇒ business carried on in Thailand
⇒ an employment exercised in Thailand
⇒ property situated in Thailand)
Residence rule
resident individuals (duration of stay in Thailand for 180 days or more on a basis year) are taxed on world-wide income, but income from foreign sources has to be remitted to Thailand in the same tax year.