A California single-member LLC operating agreement is an internal document that details the rules, management, and ownership of a limited liability company (LLC) with a sole owner. It is used to establish the company as a separate entity from the owner in legal and financial terms, thereby protecting personal assets from company exposure to debts and other liabilities. California is one of five states that legally require companies to create operating agreements, but it does not need to be filed with the state. Once completed, it is highly recommended that the document is dated and notarized in order to prove its authenticity if needed.