I found out this week that my old school cancelled my work permit without notifying me even after they had promised they would give my new school time to prepare documents before cancelling it. I am now scrambling about to leave Thailand ASAP. I wanted to find out - does cancellation of my work permit automatically cancel my work visa? Do I need to cancel my work visa before I leave? If I leave Thailand to go and apply for my non-B outside of Thailand, will I experience any issues?
TLDR : Answer Summary
The cancellation of your work permit does not automatically cancel your work visa. If you are on a Non-B visa and have not yet extended it, you can leave Thailand without issue. However, if you are on an extension related to employment, you have two options: 1) Leave without cancelling your visa extension and apply for a new visa at a Thai consulate, which may result in a fine for not cancelling; or 2) Obtain termination documentation from your employer to formally cancel your visa extension before leaving.