If a foreigner does not leave Thailand by the expiration date in their passport or on their visa, they are considered to be in the country illegally and have "overstayed". Overstay Clearance implies that the foreigner will be required to pay a fine when leaving Thailand.
If you have managed to accidentally overstay for 2 to 5 days don't worry too much. Just pay the fine imposed at the airport by the immigration officer.
BUT if you are caught by police on the way to the airport or in the airport you can be taked straight to jail. SO DO NOT OVERSTAY
If you are NOT caught by Immigration officers or Police overstay clearance fines amount to 500 Thai Baht per day of overstay, up to a maximum of 20,000 Thai Baht. And as long as your overstay does not exceed 90 days you can avoid the dreaded Black List.
BUT if your overstay exceeds 90 days, you will be banned from entering Thailand and the length of the ban is related to the length of the overstay.
In the case that you have a visa and you are applying to extend it and in order to avoid a fine, the application to extend the visa must be made no later than the next working day before the expiration date of the visa.
If a foreigner is arrested and found not to have a valid visa, the person is considered as being in the country illegally and faces not only a significant fine, but may be incarcerated in the Immigration Detention Center before being deported
Attorneys at Juslaws & Consult are well-versed in providing legal advice and offering support to clients, including cases that require overstay clearance. Due to the potential consequences for foreigners who have overstayed their visa for a long period, or who have overstayed numerous times, the assistance of an attorney can be vital. Our attorneys can accompany the client to the airport or to the Immigration Office to resolve the issue. Contact Juslaws & Consult for more information on this and other legal matters.