Mobile Telecommunications Sourcing Act

Mobile Telecommunications Sourcing Act - Amends Federal provisions concerning tax authority to deem mobile telecommunications services provided in a taxing jurisdiction as provided by the customer's home service provider. Subjects charges for such services to taxation by the taxing jurisdiction whose territorial limits encompass the customer's place of primary use, regardless of where the services originate, terminate, or pass through. Prohibits any other taxing jurisdiction from imposing any tax, charge, or fee for such services.

Authorizes a State or designated database provider to provide an electronic database to a home service provider which designates for each street address the appropriate taxing jurisdiction as identified by a nationwide standard numeric code. Requires the database provider to provide notice of the availability of such database, as well as subsequent revisions thereto. Holds harmless from any fee liability a home service provider that uses such database. Holds a provider harmless from any such liability in the absence of such a database if the provider employs an enhanced zip code to assign each street address to a specific taxing jurisdiction and exercises due diligence to ensure that each address is assigned to the correct taxing jurisdiction. Requires one specific taxing jurisdiction to be assigned when an enhanced zip code overlaps boundaries of different taxing jurisdictions. Terminates the authority to use the enhanced zip code on the later of: (1) 18 months after the nationwide standard numeric code has been approved; or (2) six months after a State or designated database provider provides such database.

Authorizes a taxing jurisdiction, or a State acting on behalf of such jurisdiction, to: (1) determine the place of primary use for purposes of appropriate taxing authority; and (2) if necessary, notify a home service provider to change the assignment of a taxing authority to reflect the appropriate place of primary use. Requires the home service provider to obtain and maintain the customer's place of primary use for taxing purposes. Provides transition provisions and special rules.