A bone anchoring device comprising: a receiving part (5, 5') for coupling a rod to a bone anchoring element, the receiving part comprising: a rod receiving portion with a first end, a second end, a central axis, and a recess for receiving a rod, the recess extending from the first end in a direction of the second end and defining two free legs (12a, 12b), the rod receiving portion further comprising a first engagement structure (14a, 14b, 140a, 140b) for engagement with an instrument (50, 50'); and a head receiving portion at the second end for accommodating a head of a bone anchoring element, the head receiving portion having a free end and being flexible for inserting and clamping the head; and a locking ring (8, 8') configured to be arranged around the head receiving portion, the locking ring comprising a second engagement structure (88a, 88b, 880a, 880b) for engagement with the instrument, wherein when the locking ring is around the head receiving portion, the locking ring can assume a locking position where the locking ring exerts a force on the head receiving portion of the receiving part to lock an inserted head; and wherein the locking ring is movable out of the locking position towards the first end of the rod receiving portion into a non locking position where an inserted head may be pivoted; and wherein the first engagement structure (14a, 14b, 140a, 140b) and the second engagement structure (88a, 88b, 880a, 880b) are configured to be engaged by the instrument and are suitable to transmit a force via the instrument onto the locking ring and the receiving part such that the locking ring and the receiving part can be moved relative to each other along the central axis from the non locking position to the locking position and vice versa. a receiving part (5, 5') for coupling a rod to a bone anchoring element, the receiving part comprising: a rod receiving portion with a first end, a second end, a central axis, and a recess for receiving a rod, the recess extending from the first end in a direction of the second end and defining two free legs (12a, 12b), the rod receiving portion further comprising a first engagement structure (14a, 14b, 140a, 140b) for engagement with an instrument (50, 50'); and a head receiving portion at the second end for accommodating a head of a bone anchoring element, the head receiving portion having a free end and being flexible for inserting and clamping the head; and a rod receiving portion with a first end, a second end, a central axis, and a recess for receiving a rod, the recess extending from the first end in a direction of the second end and defining two free legs (12a, 12b), the rod receiving portion further comprising a first engagement structure (14a, 14b, 140a, 140b) for engagement with an instrument (50, 50'); and a head receiving portion at the second end for accommodating a head of a bone anchoring element, the head receiving portion having a free end and being flexible for inserting and clamping the head; and a locking ring (8, 8') configured to be arranged around the head receiving portion, the locking ring comprising a second engagement structure (88a, 88b, 880a, 880b) for engagement with the instrument, wherein when the locking ring is around the head receiving portion, the locking ring can assume a locking position where the locking ring exerts a force on the head receiving portion of the receiving part to lock an inserted head; and wherein the locking ring is movable out of the locking position towards the first end of the rod receiving portion into a non locking position where an inserted head may be pivoted; and wherein the first engagement structure (14a, 14b, 140a, 140b) and the second engagement structure (88a, 88b, 880a, 880b) are configured to be engaged by the instrument and are suitable to transmit a force via the instrument onto the locking ring and the receiving part such that the locking ring and the receiving part can be moved relative to each other along the central axis from the non locking position to the locking position and vice versa.