What happens to a visa and work permit when leaving Thailand without re-entry?

When leaving Thailand without re-entry, the cancellation of a visa depends on the visa type. For a 90-day non-B visa, it's advised to cancel the work permit before leaving, but not doing so might not cause immediate issues. However, if the visa is an extended stay from immigration, both the work permit and the extension must be cancelled to avoid fines in the future. After returning, the work permit can be cancelled by taking it to the previous employer, which is a quick process.