Currently I am working for a company in Bangkok and hold Non-B visa. However, I am planning on to move to another company. Could anyone please let me know if I can transfer my work permit to the new company or I would have to leave Thailand and get it in again with a new permit ?

thank you in advance 

It's not "your Work Permit".  It's the company's W.P. to employ you.  

If another company wants to employ you, they have to apply for a Work Permit.

Don't cancel your current W.P. until the application has been submitted for the new one. If the new company is also in Bangkok, and with co-ordination between old & new, you should not have to leave Thailand.

 

1 hour ago, allane said:

It's not "your Work Permit".  It's the company's W.P. to employ you.  

If another company wants to employ you, they have to apply for a Work Permit.

Don't cancel your current W.P. until the application has been submitted for the new one. If the new company is also in Bangkok, and with co-ordination between old & new, you should not have to leave Thailand.

 

It IS your work permit which allows you to work at that company.

In March 2018 I walked into the Labour Dept. office and cancelled my Work Permit (with no documentation or permission from the employer).  I believe I was one of the last people who was able to do that. In my view, if you do not even have the fundamental right to cancel it, it can hardly be referred to as "your Permit."