47 C.F.R. § 90.185
Multiple licensing of radio transmitting equipment in the mobile radio service
Two or more persons eligible for licensing under this rule part may be licensed for the same land station under the following terms and conditions.
(a) Each licensee complies with the general operating requirements set out in § 90.403 of the rules.
(b) Each licensee is eligible for the frequency(ies) on which the land station operates.
(c) [Reserved]