4 USC 117 - Sourcing rules

(a) Treatment of Charges for Mobile Telecommunications Services.— 
Notwithstanding the law of any State or political subdivision of any State, mobile telecommunications services provided in a taxing jurisdiction to a customer, the charges for which are billed by or for the customers home service provider, shall be deemed to be provided by the customers home service provider.
(b) Jurisdiction.— 
All charges for mobile telecommunications services that are deemed to be provided by the customers home service provider under sections 116 through 126 of this title are authorized to be subjected to tax, charge, or fee by the taxing jurisdictions whose territorial limits encompass the customers place of primary use, regardless of where the mobile telecommunication services originate, terminate, or pass through, and no other taxing jurisdiction may impose taxes, charges, or fees on charges for such mobile telecommunications services.