Answer: check with the license people in texas, most states say you need one. also some cities make you get one, and some counties also. was just a few years ago that to operate an air cond. business in my state you just needed a business license, there was no control on the business. now it started out in one large city, and then the state got in on it, and now you have to have a state and city license. before that people who live up north would go into the boiler and drain cleaning business and then come down south in the summer with their air cond. business, ripping people off right and left and then leaving town and going back north for the winter rip offs of heating appliances.... well then cant come here no more, only the locals can rip you off now.