I have been living in Thailand for around 2 years now. I already have an official job. But I also would like to work as a part timer on weekends. I am already officially employed with a work permit. But if i get a part time job on weekend, do i need to apply for another work permit.

How do i get this stuff working legally.

Another job will require a work permit alos. If in the same area of ressponsibility of the labour office that issued the current WP, it will be added to that work permit.

It will require permission from your current employer for the extra job to be added to the work permit.

It will also require all the same paperwork that your first employer had to provide.