Yes, each state is different. In Illinois I had to get a license and a tax number. In Wisconsin just a business registration number (includes tax number). If you have employees, its federal emplyee ID number (FEIN), withholding, workers comp... (AHHHHHHH!). Also in Wisconsin, if you have sales less than $2000, you dod not need to get a tax number or colelct tax, but you must pay the tax on in-state purchases. Check your states website and Treasury Agency.