An Illinois multi-member LLC operating agreement is a document that establishes the structure of a limited liability corporation owned by more than one (1) member. The agreement outlines the company’s day-to-day operations, as well as its ownership and general policies. While signing an operating agreement is not required by law, it is strongly advised. Clarifying matters at the outset reduces the likelihood of a dispute. The operating agreement also shields members’ assets in case the company incurs liabilities. Signed copies should be retained by all signatories.