If you have a business entity, it is important to have a valid registered agent. This is not just a contact person for the company. This is a contact person in the event of a lawsuit. In the event of litigation, due process requires that there is a person on whom notice of the lawsuit can be served. If your registered agent is no longer valid, it nullifies an essential requirement of a valid business entity. If the Secretary of State finds out about it, your business entity could lose its status.
Often, the registered agent is the attorney that helped form the business. If there is no attorney, or if the registered agent is someone else, it is imperative to file an amended Articles of Incorporation, Certificate of Organization or other applicable document whenever the registered agent's information changes.