27 CFR 53.22 - Employer identification number.
(a) Requirement of application.
(1) Except for one-time or occasional filers, every person who makes a sale or use of an article with respect to which a tax is imposed by section 4181 of the Code, and who has not earlier been assigned an employer identification number or has not applied for one, shall make an application on Form SS-4 for an employer identification number. The application and any supplementary statement accompanying it shall be prepared in accordance with the applicable form, instructions, and regulations and shall set forth fully and clearly the data therein called for. Form SS-4 may be obtained from any internal revenue district office or internal revenue service center. The application shall be filed with the internal revenue officer designated in the instructions applicable to Form SS-4. The application shall be signed by:
(i) The individual if the person is an individual;
(ii) The president, vice-president, or other principal officer, if the person is a corporation;
(iii) A responsible and duly authorized member or officer having knowledge of its affairs, if the person is a partnership or other unincorporated organization; or
(iv) The fiduciary, if the person is a trust or estate.
An employer identification number will be assigned to the person in due course upon the basis of information reported on the application required under this section.
(2) Time for filing Form SS-4. The application for an employer identification number shall be filed no later than the seventh day after the date of the first sale or use of an article with respect to which a tax is imposed by chapter 32 of the Code. However, the application should be filed far enough in advance of the first required use of such number to permit issuance of the number in time for compliance with such requirement.
(3) One-time or occasional filers. A person who files a return under the provisions of section 53.151(a)(5) is not required to make application for an employer identification number. Such persons may use their social security number on any return, statement or other document submitted to TTB by that person in lieu of an employer identification number.
(b) Use of employer identification number. The employer identification number assigned to a person liable for a tax imposed by chapter 32 of the Code shall be shown on any return, statement, or other document submitted to TTB by the person.