Legal Question in Business Law in Arizona

No, you don't need an LLC in each state you do business in as long as you do not have a physical business presence in the other states. However, there are interstate matters of taxation, contracts and possible litigation which might cause complications in the future. You should talk to an attorney about what type of business it is, what you will be selling, liability concerns, and contracts to establish venue and jurisdiction, among other things.

Did this answer your question? Generally the acid test is whether you open a physical office in that state. However, failing to register when you need to can prevent you from protecting your tradename or appearing to bring or defend a lawsuit in that state.