No matter what type of Illinois LLC you start, you should create a company agreement. Here`s the reason: yes. While you won`t submit this document to the state, a company agreement is the best way to keep control of your Illinois LLC in the face of change or chaos. A company agreement works for businesses of all sizes. It allows members to outline operational procedures and guidelines. Illinois LLCs do not need to submit a corporate agreement with the state, but it is nevertheless recommended to establish one. Hi Matt, I created a single member LLC in Illinois a few weeks ago. I should have my husband`s name somewhere.