the facility call in step 3 4 it is checked whether or not the subscriber has a right to carry out the facility of the invention the subscriber can be authenticated identified on the basis of for example the authentication of the connection used by the master subscriber e g gsm network subscriber authentication or by using another authentication procedure and or separate identifier such as a pin identifier when the subscriber is verified the rights of the subscriber can be checked in the billing database and the subscriber can be allowed billing facilities accordingly if the subscriber has the right to carry out the facility i e the subscriber is a master subscriber in regard to at least one other subscriber in the same subscriber group the process proceeds to step 3 6 in this step the subscriber provides subscriber information on the subscriber to whom the facility is directed in step 3 8 it is checked whether the destination of the facility belongs to the subscriber group and if so the process proceeds to the next step in step 3 10 the master subscriber provides the amount of money to be transferred i e the amount by which the balance of the destination of the facility is increased and in step 3 12 it is checked that the amount of money is large enough to cover for example more than one call made during the daytime but nevertheless not too large e g many times the annual subscriptions of the subscriber in order to avoid potential abuse if the amount of money is of a correct size between for example 50 and 1000 monetary units the process proceeds to step 3 14 where the facility is carried.