Overstaying in Thailand is considered a criminal or administrative offence?

You pay fine at the airport.

500baht per day. Max fine 20k

Overstay recorded on pp.

No further consequences depending how long the overstay. 

2 hours ago, Tayida said:

a criminal or administrative offence?

They'll lock you up like a criminal and record it for eternity. Do not ever overstay.

13 minutes ago, tubby johnson said:

They'll lock you up like a criminal and record it for eternity. Do not ever overstay.

Fear mongering.

11 minutes ago, Lemsta69 said:

Fear mongering.

You're so brave! Go on, overstay. Do it!

It can be either criminal or administrative. If you just leave (paying the fine) after a short overstay, that is not criminal. However, if arrested (even for other offences) the overstay can, and usually will, also be prosecuted as a criminal offence, for which you can be incarcerated, deported and blacklisted from re-entering Thailand.

Done it once and officers were laughing about it and laughed more once I paid fine and said I return in 3 days after going to Singapore ! 
They didn’t seem too bothered and wrote it down on some paperwork and got me to sign saying I had paid fine and gave me a receipt.

This is the form you have to sign when getting an extension at Immigration

 

There is a difference between overstaying getting caught by IO or going to Immigration (for example flying out)

 

One advice if you do overstay, don't get caught!

 

Depends on the length of the overstay and if you are just departing normally and not found out until reaching airport immigration. 

 

When surrendering at airport immigration when leaving Thailand:

Overstay less than 90 Days = 500 Thai baht/day overstay fine (maximum 20,000 Thai baht)

Overstay more than 90 Days = 1 year ban from Thailand and 20,000 Thai baht overstay fine

Overstay more than 1 Year = 3 years ban from Thailand and 20,000 Thai baht overstay fine

Overstay more than 3 Years = 5 years ban from Thailand and 20,000 baht overstay fine

Overstay more than 5 Years = 10 years ban from Thailand and 20,000 baht overstay fine

 

When caught while overstaying:

Overstay of 1 day to 1 Year = 5 years ban from Thailand and 500 to 20,000 Thai baht overstay fine

 

Overstay more than 1 Year = 10 years ban from Thailand and 20,000 Thai baht overstay fine

You may also encounter difficulties getting a visa to other countries if they ask if you have ever overstayed in ANY country. That is one of the questions asked under the "Character" section when applying for certain visas in Australia.

 

Do not overstay.

On 2/14/2023 at 1:45 PM, Lemsta69 said:

Fear mongering.

Not at all. They will lock you up if they catch you outside the exit ports. If you're in the process of leaving, then pay the fine and be happy.

1 hour ago, AgMech Cowboy said:

Not at all. They will lock you up if they catch you outside the exit ports. If you're in the process of leaving, then pay the fine and be happy.

That's not what was said in the post I responded to. The chances of getting caught are slim to none so "don't overstay" is far too simplistic a response to such a complex matter.

 

I'm not going to go into all the whys and wherefores as I think the OP is already aware of the pros and cons of overstaying (based on a separate thread).

On 2/14/2023 at 10:09 PM, BritTim said:

It can be either criminal or administrative. If you just leave (paying the fine) after a short overstay, that is not criminal. However, if arrested (even for other offences) the overstay can, and usually will, also be prosecuted as a criminal offence, for which you can be incarcerated, deported and blacklisted from re-entering Thailand.

That's the answer I was looking for: I asked it to just to compare with other countries. For example, if I am not wrong, in most of the European countries is not a criminal offence, but just administrative.