scope:

The charging supplementary service are described in GSM 02.86 and the relevant charging principles are given in the relevant MoU documents. These services are designed to supply to a mobile user sufficient information to allow a real-time estimate to be made of the bill which will eventually be levied in the home PLMN on the MS subscriber. In the case of certain MS uses, for example a mobile payphone, this estimate could be subject to further processing (e.g. to present the charges in currency, rather than units, this may include an additional mark up).