What do I need to apply for a 30-day extension on my 60-day visa in Phuket?

To apply for a 30-day extension of your 60-day visa in Phuket, you'll need to bring certain documents to the immigration office. Specifically, you should have a completed TM30 form, a passport photo, and a copy of your entry stamp. While it's possible to visit the immigration office with just your passport, it's advisable to prepare all necessary documents to ensure a smoother process.