A business authorized by the IRS to participate in the IRS e-file Program. The business may be a sole proprietorship, a partnership, a corporation, or an organization. Authorized IRS e-file Providers include Electronic Return Originators (EROs), Transmitters, Intermediate Service Providers, and Software Developers. These categories are not mutually exclusive. For example, an ERO can at the same time, be a Transmitter, a Software Developer, or an Intermediate Service Provider, depending on the function being performed.