What form do I need to fill out to extend my tourist visa in Thailand after the 45-day exemption?

The appropriate form to fill out for extending your tourist visa in Thailand is the TM7. However, it's recommended to check if the specific immigration office you are visiting needs its own version of the TM7 form. Additionally, it's often suggested to get the forms from the immigration office directly, as online versions may be outdated. You should also prepare necessary items such as passport photocopies and recent photos for your application.