Indiana Identification Form- Corporate/Business is an official document issued by the Indiana Department of Revenue to business entities. It is used to obtain an employer identification number (EIN) which is needed to open a business bank account, file taxes, and hire employees. The types of Indiana Identification Form- Corporate/Business include the Indiana Business Tax Application, the Indiana Business Registration Application, the Indiana Subchapter S Election Form, and the Indiana Combined Employer's Registration Form. Each of these forms must be completed and submitted to the Indiana Department of Revenue in order to obtain an EIN.