What forms do I need to complete for a one-year extension of stay (Non-O 90-day Visa) in Thailand?

To apply for a one-year extension of stay on a Non-O 90-Day Visa in Thailand, you will need to complete Form TM 7. However, remember that you must also register your address using Form TM 30, and it's suggested to get the necessary documentation requirements from the immigration office well in advance, as you will need additional paperwork beyond just the TM 7. Form TM 8 for re-entry permits is optional. Be prepared with financial documents, a map, and several copies of your passport, visa, last entry stamp, and pictures.