Let's say that you have a small business, like a 1-man software consulting firm.
I know that if you do business in California, you have to pay its $800+ franchise tax.
Is there a similar requirement in every state? For example, if your clients are in NY, would you have to register your business, and pay taxes there?
What if, instead of a consultant, you are a seller on eBay or Amazon, and your customers are all over the U.S., do you have to register in every state, and pay something like the $800 minimum tax in each of them?