What is the TM30 requirement for extending a tourist visa in Thailand?

if your friend will live at your property, you as the house owner (or your wife who is actually the owner) are required to report him at the Immigration office that serves your area, within 24 hours of his arrival. However you can also register the house on the new TM30 Registration website. After being supplied with the login-data plus password, you can register your friend on this website and don't need to visit Immigration. You will see the notification of the registering, make a screenshot, print is and place inside your friends passport. Equipped with this, he will 100% receive a 30 days extension of the 30 days visa exempt entry

You can download the form and post it . Take a copy of the TM30 and the post receipt to immigration but they usually do not even ask for it.

Who told him? They should have more information.

Do it or when they go to extend they will get 1600 baht fine happened to me last week

Is your friend staying with you or staying at a hotel. Thai law requires that a property owner files a TM30 within 24 hours to report a foreigner is staying at the address. If they are staying at a hotel then the hotel should file it and they can ask for a copy from the hotel. If staying with you then your landlord should file it.