Anonymous participant 545 Don't know which country you're from, but your best bet is to read the DTA relevant to your country. No-one in this group can give you any solid advice without that information
Anonymous participant 545 It's 180 days in the calendar year. Leaving makes no difference unless you leave on day 179 and not come back for another 186 days
Of course after-tax expenses can be applied to money before it is transferred. He might also come from a higher-taxing country than Thailand, or the money he transfers may have been taxed at a higher rate before transfer. There are so many legal variables. Where only a small difference is applicable, it's very easy to legally massage numbers.
If he doesn't submit a tax return, no-one will care. The amount involved would be insignificant in the big picture, especially after allowances in both countries have been deducted