Composite frame for a window or a door, comprising - an outer auxiliary frame made of metal profiles which are connected to each other in the corner region and - a base frame made of plastics material profiles which are welded to each other in the mitre region, - a rebate region for receiving a filling, - a filling which defines a filling plane, in particular a multiple glazing, having a circumferential end face, - a plurality of glazing bridges and/or glazing blocks for fixing the end face of the filling in the rebate region of the composite frame, wherein - the auxiliary frame and the base frame in each case have means which together form a locking function so that the auxiliary frame and the base frame can be connected to each other by means of the locking function during the assembly, - the rebate region is formed in a part-region by the auxiliary frame and in a part-region by the base frame, - the locking function between the auxiliary frame and base frame is configured in such a manner that, after the connection of the auxiliary frame to the base frame and before the filling is inserted, the auxiliary frame is arranged displaceably with respect to the base frame in a plane parallel with the filling plane, and - by inserting and fixing the filling in the rebate region which is formed together by the auxiliary frame and the base frame the auxiliary frame is centred and at least substantially fixed with respect to the base frame, - characterized in that - the auxiliary frame has a single circumferential locking projection which with a correspondingly circumferential undercut of the base frame forms the single locking function between the auxiliary frame and base frame. - an outer auxiliary frame made of metal profiles which are connected to each other in the corner region and - a base frame made of plastics material profiles which are welded to each other in the mitre region, - a rebate region for receiving a filling, - a filling which defines a filling plane, in particular a multiple glazing, having a circumferential end face, - a plurality of glazing bridges and/or glazing blocks for fixing the end face of the filling in the rebate region of the composite frame, wherein - the auxiliary frame and the base frame in each case have means which together form a locking function so that the auxiliary frame and the base frame can be connected to each other by means of the locking function during the assembly, - the rebate region is formed in a part-region by the auxiliary frame and in a part-region by the base frame, - the locking function between the auxiliary frame and base frame is configured in such a manner that, after the connection of the auxiliary frame to the base frame and before the filling is inserted, the auxiliary frame is arranged displaceably with respect to the base frame in a plane parallel with the filling plane, and - by inserting and fixing the filling in the rebate region which is formed together by the auxiliary frame and the base frame the auxiliary frame is centred and at least substantially fixed with respect to the base frame, - characterized in that - the auxiliary frame has a single circumferential locking projection which with a correspondingly circumferential undercut of the base frame forms the single locking function between the auxiliary frame and base frame.