What is the penalty for expired retirement visa in Thailand?

Overstaying in Thailand is illegal so if you know that you are overstayed you better fix it as soon as possible because you will fine 500 baht per day or if you overstay more than 40 days you need to pay the fine the maximum which is 20,000 baht. If you get caught being overstay in Thailand you are in risk of being arrested, imprisoned and you may also be banned from returning to Thailand depending on how long you have overstayed your visa.