In the USA, it's down to what a city, county, and/or state has decreed.
Most states require filing for a business license. Cities and counties may require a business license fee on top of that.
You'll want to do your research to see what type of business entity is best for your situation. The first consideration in that respect is tax liability. Make certain you establish yourself in a way that you're not overcharging yourself.
I believe most states have a minimum threshold for tax reporting, which is usually around $10,000 in annual revenues. Thus, new businesses would only be obligated to pay fees.