26 CFR § 36.3121(l)(10)-2 - Identification.
(a) Domestic corporation. A domestic corporation which has secured, or is required to secure, an identification number as an employer having in its employ one or more individuals in employment for wages is not required to secure an identification number under the regulations in this part.
(b) Employees. Every employee performing services covered by an agreement shall have the same duties in respect of an account number as would be the case if the employee were performing services in employment for the domestic corporation.