A method and system for changing subscribers in communications networks. In communications networks, more and more information providers (referred to as content providers) are making available WML/HTML pages (data contents) on their servers which subscribers can request and download onto their terminal. The present invention is directed to a method and a system which charges information transmitted via a communications network on the basis of its content. The criteria for classifying a WML page in a billing system are the information provider's. A "WAP gateway" constitutes the interface between the subscriber and the WAP data world or Internet data world. All the WML/HTML/XML content called by subscribers passes through a WAP gateway. According to the present invention, a network unit responds to the charging inquiries for subscribers.