Each new entity, such as a corporation or limited liability company (LLC), is required to have a new employer identification number (EIN) for federal tax purposes (this is not the same as a
state tax number). This is true because the new entity is considered a legal entity separate and apart from the individuals who operate it. This is one of the reasons for limited liability protection. An exception to this rule is a one-person LLC. In the case of a one-person LLC, the entity is usually disregarded for tax purposes only (the entity is retained for purposes of liability protection), and the person continues to file taxes using their social security number. Therefore, a new EIN may not be required.