Thailand: visa overstay, beware to consequences!
To ease tourism, and as long as you are staying in Thailand less than one month, there is a visa exemption for citizen of many countries, including US, France and several other European countries. If you plan to stay in Thailand for more than one month, you must apply for a visa in an embassy or in a consulate of Thailand.

There is a simple and legal way to extend your stay: you can leave the country for a few days to visit a neighboring country, for instance Laos, and once you are back in Thailand, a new one-month stay on Thai territory is allowed.
This practice, quite similar to the “run visa”, which is used by many almost permanent residents in Thailand, is suitable for all those who wish to spend a long vacation in the region.
In the example below, an arrival on the 30th October allows to stay in Thailand up to but no later than January the 2nd, providing you have left the country once in the meanwhile.

Si you want to settle permanently or stay on long periods of time in Thailand, we advise you to apply for a visa adapted to your situation.

Once the deadline on your passport has passed, you will have to pay a fine of 500 baht per day of delay, with a maximum of 20,000 baht, which is about 500 euros, a sum equivalent to the price of a return flight in low season. Be aware that check-out may last much longer, especially if you seem to be in a hurry or arrogant. And you may also be banned from re-entering the Kingdom of Thailand.
Even worse: if you are controlled in the country without a valid visa or residence permit, you may be deported to your home country, and there is even a risk to be sent a certain time in prison.
The Thai authorities plan to tighten controls in the coming months, in particular for the tourist visa 90 days maximum duration.

If you own a property in Thailand, it is possible to obtain a retiree or an investor visa. You will be able to renew this document as long as you stay the owner of this property. This is one of the advantages of Thailand for people enjoying long stays. You must keep in mind that this is not the case everywhere. For example, owning a property in the U.S. does not guarantee that you can stay on American territory.