This thesis deals with legal issues arisen from consumer-activated payment orders, regarding credit transfers, which are initiated via the Internet under an agreement (about using Internet-services) previously entered into between the bank and the payer (or the originator). This Internet-service is in the thesis called Internet banking. More and more customers, both consumers and others, activate such payment orders on-line. Payments or payment orders are not a new phenomenon but in the thesis they are dealt with from an electronic perspective. The thesis? subject matter is the bank-customer relationship from a Swedish private law perspective. Three questions are of central concern for this thesis. Firstly, how is the private law regulation regarding payment orders made? Secondly, what is the law of substance regarding payment orders initiated via the Internet? Finally, what legal implications, if any, occur when a payment order is initiated electronically via the Internet? The thesis examines different aspects of the bank-customer relationship. One aspect is, from a customer's point of view, the right to use Internet-services. Another aspect is payment by mistake but also the right of revocation or countermand. Yet another aspect is the bank's obligations as an intermediary as regards to payment orders. Furthermore, the thesis examines how to produce information generated electronically as evidence in a court of law. An overall question in the thesis is whether banks are subject to a higher degree of risk when using the Internet as a communication channel. In the thesis it is argued, the answer to that question is no.