A filter system (100) for filtering a fluid, with a front-end inlet (102) and outlet (104), and comprising: at least one filter element (10); a filter housing (108); a coupling device (30) for coupling the filter system (100) to a receiving means (32) external to the filter system; and a seal holder (16) having a seal (18) for sealing the filter system at the receiving means (32). In addition, the coupling device (30) has one or more coupling elements (36) that can be at least partially introduced in an axial direction (L) into a coupling contour (34) arranged in the receiving means (32), by means of a sliding-rotating movement, such that the 20 filter system (100) is held and locked in the receiving means (32) in an end position (38). Also disclosed is a combination of a filter system (100) together with a receiving means (32).