When should I file the TM30 immigration residence form if I'm staying temporarily with family in Thailand?

Within 24 hours

File it as soon as possible preferably in 24h.

I flew in BKK and took me 7 days to get my wife home in North. We stayed 4-5 different hotels on the way up north. Non of the Hotels reported me to Immigration.

At my local Immigration desk they said i might get problems if trying to extend my Non O visa. So the Immigration worker let me pull out my booking,com account and choose random last booking to call the hotel and ask why they didnt report me. So i got cleared it wasn't my mistake. Immigration worker said to me she will write extra note for my Extension application once i am back at in Immigration department to apply extension of my stay.

you have 1 day to file after landing

Have you stayed there before? when I stay with a Thai friend, we just head to immigration, he brings his house book and we fill out the form, give it to the officer and she returns a copy back to me. Simple process, you shouldn’t have any problems. Good luck moving to Thailand 🤞

I would make sure your house has a hot shower and ac units. People here are accustom to cold showers. If not stay Ina hotel. They are dirt cheap

The owner of the property you're staying at files the TM30 within 24 hours of your arrival

You have 24hrs grace time to file a TM30 when residing at an address in Thailand.