An electronic money server groups a parent who owns a parent mobile phone and children who own child mobile phones to be registered as a family, and credit information of the parent is also registered. When the child accesses the electronic money server by using the child mobile phone and specifies a money amount to request family charge, the electronic money server requests the parent mobile phone for permission of the family charge. When the parent grants the family charge, the electronic money server allows the parent mobile phone to decrease a value by the money amount specified by the child and to make the family settlement, and allows the child mobile phone to increase the value by this money amount and to effect the family charge. Further, the child mobile phone can accept issue of credit from a credit server on credit of the parent, thereby effecting the family charge.