A receiving part for coupling a bone anchor to a rod is provided,wherein the bone anchor includes a shank (2, 2′) for anchoring in a bone or a vertebra, the receiving part (3, 3′, 3″, 3′″, 30, 30′, 30″, 30′″) including a first end (3a)and a second end (3b), the second end (3b) being connected to the shank (2, 2′),a bore (7) extending from the first end (3a)into the receiving part for receiving a fixation device (9), the bore having a bore axis (C),a recess (4, 4′, 4″) for receiving a rod (100, 1000), the recess being open at the first end (3a) of the receiving part for allowing insertion of the rod, wherein when a rod is inserted into the recess a longitudinal axis of the rod extends substantially perpendicular to the bore axis (C), wherein the recess (4, 4′, 4″) comprises opposing sidewalls (4b) on at least one side of the bore (7)；characterized in thata resilient retention element (40, 400, 400′, 400″, 400′″) is provided on at least one of the opposing sidewalls (4b), wherein the resilient retention element is deflectable toward the at least one side wall (4b) when the rod (100, 1000) is inserted.
