: Its not official, but note that if you're on Tourist Visa, you need to convert it to Non B, before it expire then its only from then that you can pursue a work permit. But I'm sure since you have been sent by a company, you will likely have Non imm B. It expires in 3 months and you need to have made your Work permit and do a one year extension. All these process may required a time frame of 2 weeks to a month depending on the circumstances. Note that most principles are not same in different "ChangWat" (Provinces).
As per Thai law, you must brandish a Work permit first, but most at times, there can be a grace period (not official) to enable you acquire one while you move on with your job normally.
