49.4253-9—Exemption for certain interior communication systems.
(a) In general.
The taxes imposed by section 4251 do not apply to amounts paid for wire mileage service or wire and equipment service, if such service is rendered through the use of an interior communication system.
(b) Interior communication system.
The term “interior communication system” means any system:
(1)
No part of which is situated off the premises of the subscriber, and which may not be connected, directly or indirectly, with any communication system any part of which is situated off the premises of the subscriber; or
(2)
Which is situated exclusively in a vehicle of the subscriber and which is not connected with a communications system.
(c) Examples.
The following are examples of interior communication systems: