27 CFR § 24.47 - Execution of IRS Form SS-4.
(a) Preparation. The application on IRS Form SS-4, together with any supplementary statement, will be prepared in accordance with the form instructions and applicable regulations. The application will be filed with the director of the internal revenue service center as instructed on the Form SS-4.
(b) Signature. The application will be signed by:
(1) The individual, if the taxpayer is an individual; or,
(2) The president, vice president, other principal officer, or other person authorized to sign, if the taxpayer is a corporation; or,
(3) A responsible and duly authorized member or officer having knowledge of its affairs, if the taxpayer is a partnership or other unincorporated organization; or,