Can I Leave Thailand the Day After My Visa Expires Without Penalty?

If you ask your employer to write the letter of termination of contract with a date a few days later than the day you actually stand in front of the class, you give yourself a few days spare to travel.

okay, then you go and cancel your work permit at the Ministry of Labor, with the documents you get there you visit the Immigration Office and cancel your Extension of Stay. Both need to be cancelled on your last day of work, you can do this in advance to make travel plans or wait till the last day and leave that day. If you can not leave that day you may apply for a new Extension of Stay which will be not approved and you get 7 days to leave the country.