What do I need for a 30-day tourist visa extension in Thailand?

To apply for a 30-day extension of stay on a tourist visa in Thailand, you will generally need to bring several copies of important documents. Although the exact requirements may vary by location, it is advisable to prepare copies of your passport (including the visa page), the immigration form, and any supporting documents that may demonstrate your travel plans or financial stability. The Koh Tao office is known for its more relaxed approach, and getting your copies ready beforehand can save you a small amount of money.