Mobile Telecommunications Sourcing Act

States that all charges for mobile services provided by the customer's home service provider (provider) are authorized to be subject to tax, charge, or fee by the taxing jurisdictions whose territorial limits encompass such customer's place of primary use, regardless of where the mobile services originate, pass through, or terminate. Prohibits any other taxing jurisdiction from imposing a tax, charge, or fee for such mobile services. Provides tax limitations.

Authorizes a State to provide an electronic database to a provider, or allows a designated database provider to provide such database to a provider. Requires such database to designate the appropriate taxing jurisdiction identified by one nationwide standard numerical code. Outlines additional database requirements. Requires a State or database provider to provide notice of the availability of such database in that taxing jurisdiction.

Holds a provider harmless if neither a State nor designated database provider provides such a database, as long as the provider employs an enhanced zip code to assign each street address to a specific taxing jurisdiction for each appropriate level of taxation and exercises due diligence to ensure that such information is correct. Outlines procedures to be undertaken by a provider when the enhanced zip code overlaps boundaries of taxing jurisdictions. Terminates the exclusion from liability of a provider acting in such manner on the later of: (1) 18 months after the nationwide standard numeric code has been approved; or (2) six months after that State or designated database provider provides the database for such use.

Authorizes a taxing jurisdiction, or a State acting on behalf of any taxing jurisdiction within such State, to take appropriate action to correct erroneous data concerning a customer's place of primary use.

Makes a provider responsible for obtaining and maintaining each customer's place of primary use for tax purposes. Allows the provider, for two years after the enactment of this Act with respect to existing service contracts, to treat the customer billing address as that customer's place of primary use.

Excludes the Federal Communications Commission from jurisdiction over the interpretation, implementation, or enforcement of this Act.