A Massachusetts single-member LLC operating agreement is used by a sole proprietor to establish the ownership, purpose, and procedures of a limited liability company. While LLCs are legally allowed to operate in the state of Massachusetts without an operating agreement, the document formalizes a legal separation between the company and the owner, thereby offering protection for personal liability and assets in the event of company bankruptcy or litigation. In addition, without implementing the company’s own internal regulations and rules through an operating agreement, the company is subject to general state rules governing LLCs.