If you are American and in the States get a Charles Schwab Investor Checking Account before leaving. All ATM fees worldwide are rebated at end of the month. Also get a Wise Account. Link all you bank accounts and your Wise together. You can either pay rent cash thru ATM withdrawal using Schwab or via transfer to Landlord's bank account using Wise.
Both DTV and 60 days visa free were announced as temporary measures so it ending was baked in from the start. As far as extensions go, I think everyone understands that isn't the way to go with this visa. Just leave and come back and avoid immigration office.
Visa itself doesn't indicate justification, so it would likely only be issue if you try for the extension at immigration. And booking another dental appointment would probably be easier than gathering all the paperwork to re-justify remote worker status, especially since Immigration may require different proof than your Embassy did. The remote thing was always billed as "work-ation", not temporary residency like LTR, so if they start imposing restrictions on stay or re-entry I think they'll do it broadly and it won't matter how you got the visa.
We all do a lot of things. The issue is not that we pay taxes but rather what Thai Embassy is doing with the return. Possibly just to confirm your work information you submitted for DTV application but also possible these Embassies have implemented some kind of unwritten net income requirement beyond the 500k in bank.
He asked why Thai Embassy wants tax returns. This is a fair question since not all Thai Embassies ask for it and it is not part of stated requirements for the visa. So what are they using it for? Could be the Embassies in these countries are enforcing some kind of unwritten net income requirement beyond the 500k in the bank. If so, that fact and what level they are enforcing would be valuable for people to know.
It is called "visa exempt" and for Australians you now get stamped for 60 days when going thru airport immigration. Using the phrase "on arrival" is problematic as there is a totally separate thing called "visa on arrival" which is an actual visa that lasts 15 days which you apply for when you land but is not open to Australians (or any Anglo-countries) and has nothing to do with your situation. You are not getting a visa. You will just stamped when presenting your passport with a stamp entitling you to stay for 60 days. So your agent is misinformed.
It means you have to get a tax # and pay tax on income brought in to the country. Your assumption on double taxation hinges on whether a double taxation treaty exists between Thailand and the other jurisdiction in which you are paying tax.
Did you originally enter on a Tourist Visa or did you enter Visa Free? If it was the latter it definitely wouldn't be totally unheard of as that would be 4th visa free entry and you would have been looking at near 8 months of continuous living on visa free entry and extensions. And you didn't really say what was going on last year so if you were in Thailand end of last year that looks even worse.