If you physically do all your work in one state you have no problems. When I was consulting I had a VERY booked travel schedule where I was doing an awful lot

If you physically do all your work in one state you have no problems. When I was consulting I had a VERY booked travel schedule where I was doing an awful lot of work while flitting between multiple aggressive high-tax jurisdictions, so my accountant went through the specifics. Again, took only a couple of minutes while reviewing my travel log. Relatedly, if you incorporate, your accoutant can walk you through where you should do that. (Delaware C corps are the gold standard in the Valley due to investors liking Delaware's laws/courts. I didn't need to optimize for investors so I have LLCs in Nevada, because they're fairly cheap and can't cause state income tax since Vegas means Nevada will never have one.)