What is involved if I start a business under an assumed name?
In Illinois, under the Assumed Name Act, if you want to operate as a sole proprietor under any name other than your own, you have to register with the local county clerk’s office. In fact, you have register with the clerk regardless of the entity you choose. Your local bank should be able to supply you with the papers you’ll need to fill out and information on the costs that you’ll incur.