Abstract: A method of buying a service or a product using a telephone apparatus, in which method the service operator has the equipment to identify the customer, who sends a message with a telephone apparatus to the service operator in order to place an order for a service. The method includes a contract between customer and service operator, whereby, when the customer calls the service operator from a contracted telephone number the service order will be accepted, when the service operator identifies the caller number to be in accordance with the contract, whereby the service operator switches on the service wanted and directs the charge of transaction to the identified customer.