Attachment, fastening and/or locking system for containers on an attachment device, in particular on a carrier such as a luggage carrier on which attachment points are attached and/or can be positioned, which correspond with receiving elements arranged on a bag or a container and detachably fasten the bag or the container to the carrier in a defined position by means of at least one lower guide element attached on the rear side of the bag or container and by means of two upper receiving elements attached to the rear side of the bag or container, wherein the two receiving elements (3, 4) attached in the upper region to the rear side (1) of the bag or container are arranged along a circular path and are designed with a substantially continuous guide groove (15), following the circular path,comprising a projection for receiving a mushroom-shaped fastening means, which is arranged on the luggage carrier. Each receiving element is equipped with a spring-loaded tilting lever mounted for rotation about an axis and one end of each tilting lever extends in the direction of the top edge of the bag or container and the other bevelled end oriented in one direction extends into the guide groove with the projection of the receiving element and can be displaced only in one direction against the spring force by means of a mushroom-shaped attachment means that can be pushed through..