Can I just pay a fine at the airport for overstaying my 30-day visa in Thailand?

The best course of action when your visa is about to expire is to seek an extension from the local immigration office rather than risk overstaying. The fine for overstaying in Thailand is 500 baht per day, which can amount to 2,500 baht for five days. An extension costs 1,900 baht and can save you both money and potential problems, such as receiving an overstay stamp in your passport and facing legal issues if stopped by authorities.