Hi everyone ,i have a work permit and nonb visa ,had a new job offer .what hassle would i after go thru ie when i leave my  company, will i have to leave thailand to go thru all the process again 

Is your new job offer in the same province ?

Just now, allane said:

Is your new job offer in the same province ?

yes it is 

I assume you have an extension of stay based upon working not a valid non-b visa.

It is possible to change employers without leaving the country.

The main thing your new employer must do is apply for your new work permit and obtain a work permit application approval letter.

You would then need a letter a from your current employer stating your the last day you will be working to have your current extension cancelled. Then on that day you would apply for a new extension with supporting documents from the new employer and the approval letter.

You would then cancel your current work permit and have your new one issued.

On one occasion, I did this, and all within a half a day or so. 

I. turned in my old WP at the Labour Dept. I think I did that a day or two earlier. On the day in question, I met with the Personnel Officer from my old job in the Immigration office at 9:00 a.m.,, did the necessary paper work, sat there, and then met with the Personnel Officer of the new job in the Immigration Office at 10:;; a.m. Probably, all was completed by 11:00 a.m.

Make sure that you stay on good terms with the key people at the place you are leaving. No need to leave the country. 

Thanks alot allane and joe ,