I understand, but if I ever want to get PR, they will need to see 2 or 3 years of what's happening with my bank. The big question is, will they complain about it?
And if I make enough money to reach the yearly amount which forces me to provide my info for tax, won't I get in trouble when they see that it's not noted in my work permit? (please note that the current amount is still low, but with a bit of effort, it'll be an easy way to make a good amount of money, so I'll be sure if it will be possible, tricky or just not possible)
I do not know any teacher who doesn't teach extra classes after school. Some even teach the children of police or someone at immigration lol. So, somehow it seems to be allowed, but like always in Thailand, the answers are either 'yes, but...', 'no, but....' or 'technically...'.