A method for accounting information handling in an interworking is provided. A method for processing accounting information by a gateway device includes sending an accounting request message to a first electronic device, and receiving a response message from a first electronic device, the response message responsive to the accounting request message. The accounting request message is related to a communications device attached to the first network. The method also includes processing accounting information. The processing is based on the response message, the gateway device and the first electronic device are part of the first network, the communications device is accessing a second network through the first network, and the communications device has a subscription only with the second network.