Embodiments attribute network data transfers to applications executing on a computing device. A data transfer service executes on the computing device to receive and process data transfer requests. The data transfer requests, populated by the applications, have identifiers attributed thereto to enable monitoring of the network data transfers per identifier. For example, network data transfers associated with different mail accounts of a mail program or different web sites of browser are attributed separately. Data usage statistics relating to the network data transfers for each identifier may be generated and presented to the user for review.