Determine in which court you should file your lawsuit. If you and the LLC reside in the same state, file the case in the county or city in which the problem occurred. If you and the LLC reside in different states, you may be able to file your case in federal court if the damages you are seeking are high enough. The Federal Rules of Civil Procedure specify the requirements for filing in federal court.
Draft a complaint. The complaint is the initial document that you file with the court to begin a lawsuit. Your complaint should list you as plaintiff, the official name of the LLC as defendant, and include a clear and concise explanation of what you believe the LLC did wrong that entitles you to compensation. Both state and federal courts have rules of procedure that specify the format for complaints, and some courts offer forms you can use to create a complaint. The court clerk can provide information about complaints and forms, but not legal advice.
File a copy of your complaint with the court. Mail a second copy of the complaint to the LLC, along with a summons. The court in which you filed the complaint will have forms for the summons. You may also serve the complaint on the LLC in person by hand-delivering it to the LLC's principal place of business. If you have an attorney, your attorney can serve these documents for you and will also include a notice of appearance, which explains that your attorney is representing you. If you are representing yourself, you do not need a notice of appearance.