A polyaxial bone anchoring device is provided comprising a bone anchoring element (1) having a shank (2) to be anchored in the bone and a head (3) a receiving part (5) coupled to the shank and configured to pivotably receive the head, and having a channel (56) for receiving a rod (6) and a central axis (C) a pressure member (7) arranged in the receiving part and configured to exert pressure onto the head to lock the head in the receiving part a locking member (8) that is insertable into the channel, the locking member comprising a top end (81) and a bottom end (82) facing the pressure member a deformable first portion (85) and a second portion (84) provided at the bottom end wherein, when the locking member is advanced into the channel in the direction of the central axis (C), first the deformable first portion (85) comes into contact with the pressure member (7) and is deformed resulting in a load applied to the pressure member that clamps the head, and thereafter the second portion (84) comes into contact with the rod and clamps the rod.
