The invention relates to a coupling system for connecting at least one supply line between a towing vehicle and a trailer, the first end of said at least one supply line being attached to the towing vehicle in a fixed manner, and the second end thereof comprising a connector that can be connected to a supply line interface of the trailer. The aim of the invention is to provide a coupling system for the supply lines, by which means a complicated operation between the trailer and the driver's cab of the towing vehicle is avoided. To this end, a coupling system is provided, whereby the supply line interface can be displaced out of a traveling position into an operating position.