Does the owner of a house need to fill out a TM30 form if I stay with them in Thailand?

In Thailand, if you stay at a Thai friend's home, the owner must register your stay by filing a TM30 form. This can typically be done online rather than in-person at immigration. Failure to lodge the TM30 could cause issues when you change your residence or apply for visa extensions, possibly leading to fines. If you move, the TM30 for your new address will supersede any prior stays, meaning that the past stays without registration won't be pursued, but it's best practice to file the TM30 to avoid complications.