B) it is POSSIBLE, that thai revenue 'outsource' this to the banking system. Your bank may ask for a tax number or just withhold tax from ny incoming payments on the basis that anyone with a Thai bank account is highly likely to be tax resident. Genuine non tax residents could have to present at Thai Revenue to prove they re not tax resident.
A) when leaving the country it is POSSIBLE (note the meaning of the word) that Thai Immigration could ask why you don't have a Tax File Number if your stay is more than 180 days in the tax year. After all if it is made a condition of a visa that you get a Tax number after 180 days it really would be an immigration issue.
oh well, you worked it out. As previous comments it's really about the risk of overstaying. If they have multiple entry stamps in passport, and a job and family and reasonable financials then I think it's pretty easy. The more of these missing it gets harder and harder. I also have a friend who has his GF currently in Aus , no job, no overseas prior, little family connections in Thailand and she got the visa first go, via an agent.
I'm not sure that is the case. Do you have recent personal experience of the process? I had a friend come over in November last year and the visa came in a few weeks, and no questions asked.
it may or may not work now. They have recently turned the screws again. It just gets harder every year, and will continue I think. They are now starting to ask Aussies for their TFN tax file number in Australia. A recent change.
'certificate of residence from immigration which needed a rental contract and landlords id copy' So you had a rental contract on a 30 day visa? Or was it a longer term visa?