I currently have a Non-O marriage VISA and a Work Permit (new only 2 weeks old), VISA due to expire next month. 
My employer and I want to transfer it to a non-B VISA and recommend I leave the country to get it e.g Laos, get my non-B, re-enter Thailand and they will sort out the year extension. 

 

My employer said I have to go to CW immigration to cancel my current VISA before hand. It is a single entry VISA so I thought if I left the country it would just cancel it automatically. Is my employer correct? I have to cancel it in Thailand immigration first? 

Next question is about the non-B application process in Vientiane, Laos; is it a good place to do it? Is it smooth? I have been told some places are better than others. 
I work in a big International School, Work Permit, the school will provide all the documentation. 

Vientiane is generally a good location to apply for visas. If you have all the required documents, it should go smoothly. Note that you need an appointment to apply in Vientiane (https://thaivisavientiane.com/)

21 hours ago, BritTim said:

Vientiane is generally a good location to apply for visas. If you have all the required documents, it should go smoothly. Note that you need an appointment to apply in Vientiane (https://thaivisavientiane.com/)

Thank you. 
You already answered my first question on cancelling my VISA. 

On 10/26/2023 at 5:54 PM, Benbkk26 said:

It is a single entry VISA so I thought if I left the country it would just cancel it automatically

 

Correct, CW cannot cancel a visa, only an extension of stay. You leave to get your Non-B and your single entry Non-O will become defunct.