As the OP is an advertisement for a help in setting up a Thai company it should be taken with a grain of salt.
Worth noting, the OP did not actually quote Section 41 of the Thai Revenue code. The reason for this is it contains a very big loop hole that is easy to use to avoid the Thai tax liability on derived assessable income
Section 41 A taxpayer who in the previous tax year derived assessable income under Section 40 from an employment or from business carried on in Thailand, or from business of an employer residing in Thailand or from a property situated in Thailand shall pay tax in accordance with the provisions of this Part, whether such income is paid within or outside Thailand.
A resident of Thailand who in the previous tax year derived assessable income under Section 40 from an employment or from business carried on abroad or from a property situated abroad shall, upon bringing such assessable income into Thailand, pay tax in accordance with the provisions of this Part.
Any person staying in Thailand for a period or periods aggregating 180 days or more in any tax year shall be deemed a resident of Thailand.
As long as you don’t bring the income in until 2 years after you have earned it, it is not taxable in Thailand.
Then, just to be sure you don’t owe Thai tax, you take the money and invest in an income paying mutual fund and then the income is again exempt from Thai Tax.
Section 42 The assessable income of the following categories shall be exempt for the purpose of income tax calculation:
23) Income from sale of investment units in a mutual fund.
(24) Income of a mutual fund.
You then use the income from the mutual fund to show required income for the retirement visa.
The problem does remain that in general, everybody owes tax on their income somewhere and it is getting harder and harder to slip between the cracks with countries that do not require a declaration of worldwide income such as US citizens have always had to do.
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