All telecommunications providers that offer interstate and international voice and data, private line, directory assistance and other regulated services in the United States are required by the FCC to contribute to the FUSF. All retail customers currently purchasing interstate and international voice and data services are subject to the surcharge. Wholesale customers, those registered carriers that resell FTS services, may be exempt from the surcharge if they contribute to the FUSF directly. FCC regulations specify that carriers pay the FUSF charge on services sold to end users.  As such, resellers that are wholesale carrier customers may be exempted.
You can find more information about the Universal Service Fund at: www.fcc.gov/general/universal-service