Good question and kudos to you for checking it out before blindly launching into something without all your ducks in a row. The answer is yes, or no, and it depends.
If you are thinking of employing people, then you will likely need one. If not, it's often no, but that also depends on if you will be having customers come to your home. Your best bet is to go online at your local city or municipal website site and look into their regulations for your area and your industry. You can also pick up the phone and call them.
These regulations will be different from one community or municipal district to the next