NEVER ask such questions in Facebook! Despite what people don't do or have experienced, to file in the TM30 is mandatory (and yes, you, the tennant, gets the fine as soon as you go to immigration, or are pulled over. And yes, as long as you are not going to be involved with immigration, there is no real need. But again: it is mandatory)...
Same discussion goes for carrying your passport when leaving your hotel. Also mandatory. But most people will say: "I always carry a copy. Never had a problem"... It still is mandatory...
Just go to the official Thai government sources. It is all explained there... Do your own research. Here on Facebook you will only get more confused...
YES! And the fact that you don't do it changes nothing. TM30 is mandatory. And when you come back from a weekend in a different province, say to a hotel or a friends house (btw they have to file too when you stay), you have to file again at your girlfriends house. Every time. But you are right, I didn't do it either... But that meant I didn't stay 30 days longer... I didn't want to risk the hassle and rejection.
I got in on Oktober 23, staying for 58 days (back in the Netherlands now).
I was going to stay at my girlfriends place, and travel a bit together.
At the airport no questions were ask. Just a check of my passport (not even the boardingpass). So no inquieries about where I was going to stay (I had her address prepared on print in three languages). No proof of flight back or even when. I just got a stamp... mind you, this was my third entry this year. First in January with a visa (it was longer than 30 days). Then, after a month in Australia, I came back for 12 days (the love is strong 😊), 30 day visa exempt. And, this time 60 days exempt. Easy peasy...
This Thursday I flew back home. I checked through customs with passport (self)scan and facial recognition. No questions ask, no proof of where I had been (TM30, which we did not enter. But that could have been a problem if I had decided tot extend 30 days at immigration. It was tempting, but I didn't want any hassle and maybe have to convince an officer that I am really a tourist visiting his girlfriend, and maybe get rejected because of playing with the exempt system. And you only prolong the hurt of leaving for 30 days).
I entered Oktober 23, visa exempt, from the Netherlands. No questions asked (not even where I was going to stay, or how long). I was in line for about 30 minutes (it was busy). The digitale systems speeds up things.
Never use an agency. It's a waist of money. Entering Thailand is childsplay. Just choose the right system/visa up front.