I went to Bangkok Immigration and changed my tourist visa to a non-immigrant ‘O’ visa for the purposes of volunteering at a hilltribe school in Mae Hong Son. It was issued on October 24^th and is valid for 90 days before which I must get an extension for it. I want to extend it for 1 year with a multiple entry permit. Does anyone know the procedure for this? And if I need a work permit beforehand to be able to do this? Thanks in advance.

I went to Bangkok Immigration and changed my tourist visa to a non-immigrant ‘O’ visa for the purposes of volunteering at a hilltribe school in Mae Hong Son. It was issued on October 24^th and is valid for 90 days before which I must get an extension for it. I want to extend it for 1 year with a multiple entry permit. Does anyone know the procedure for this? And if I need a work permit beforehand to be able to do this? Thanks in advance.

This thread should help.

http://www.thaivisa.com/forum/Volunteer-Vi...+visa+extension

You will certainly need a WP before hand. Without one you are not allowed to do volunteer work and they will not extend your permission to stay.