Perhaps time to post this here again.

Overstaying your “admitted until” date in your passport is breaking the law.

Many times on here people ask is it ok to overstay - 1, 2, 5 days etc. The fine at the immigration exit desk is 500 baht per day of overstay. Some airport immigration officers will waive the fine if it is only 1 day, but you’ll still get a small stamp in your passport in Thai saying “overstay fine waived as under 24 hours”. 100% you’ll be fined at a land border

HOWEVER if you are stopped inside the country for any reason - like at a police check point - even on your way to an airport or border crossing then be prepared for a whole lot of trouble.

The police may arrest you as you have broken the law. If they do you’ll be fined in court and then sent to the nearest Immigration Detention Centre, where you will be kept until you buy a one way ticket back to your home country. If you don’t have the funds for that you will be kept there until you find some means of raising those funds. Once you have your ticket, you will be deported and blacklisted from entering the country for up to 5 years.

Sounds dramatic but it sometimes happens. 500 baht a day sounds cheaper than an extension for 1900 baht at a local immigration office but in the overall scheme of things it is never wise to overstay.

For those who want to argue that “I’ve never had an issue on overstay - so you’ll be fine” Is akin to saying “I got away with breaking the law - so you will too”.

There have also been reports of some having issues with getting visas or entries to other countries because of their overstay stamp in Thailand. Russia and Singapore spring to mind. It may not affect you coming back to Thailand but it could potentially be an issue going somewhere else.