Could someone tell me the steps to take when changing jobs with regards to the Non-B extension and the Work Permit (without leaving the country)?
The jobs will be in a different city, 1 hour apart from each other.
TLDR : Answer Summary
When changing jobs in Thailand while holding a Non-B extension and work permit, it is crucial to coordinate closely between your current and new employers as well as the immigration office and the Ministry of Labour. You need to cancel your current extension based on your current employment and apply for a new extension based on your new employment. If the new job is in a different city, ensure that both employers are willing to cooperate and that the work is handled through the same immigration office to simplify the process. Be aware that you will also need to obtain a new teaching license if applicable.