See "Articles of Organization". When forming a limited liability company "LLC" in a state you will generally begin the process by filing a certificate (legal form) with a designated office in the state. This form goes by various names in different states. Caution - while this can be done on line inexpensively in many instances, there are actually a host of nuances of what you need to consider when preparing such a certificate. Its often cheaper and safer in even the short run to have an attorney help you address this. Its not only the minimum essentials to get organized. You really need legal judgement to determine if your business form (LLC or otherwise) is correct for your situation, whether you need ancillary entities or documents (e.g., a separate LLC to own passive assets used in the business), etc. The tax status for the entity should be addressed (disregarded entity, partnership, S corporation, etc.).