An autoinjector comprising: a case; a needle shroud telescopically coupled to the case and movable between a first extended position, a retracted position and a locked second extended position; a carrier slidably arranged in the case and adapted to hold a medicament container, the carrier movable from a first axial position to a second axial position relative to the case; a collar slidably disposed in the case, the collar coupled to the carrier; and a trigger button operably coupled to the carrier, wherein the carrier abuts a rib (2.3) in the first axial position and the needle shroud is in the first extended position and disengages the rib (2.3) when the needle shroud is in the retracted position and the trigger button is pressed to advance the carrier to the second axial position, the autoinjector further comprising a control spring biasing the collar in a distal direction relative to the case, a plunger slidably coupled to the carrier; and a drive spring biasing the plunger relative to the carrier, characterized in that the case includes said rib (2.3), wherein the collar is also rotatably disposed in the case and coupled to the needle shroud; wherein the collar includes a shroud boss adapted to engage a shroud slot in the needle shroud and a carrier boss adapted to engage a carrier slot in the carrier, wherein the collar, dependent on the relative axial and rotational position in relation to the needle shroud and the carrier, couples the force of the control spring to either the carrier or the needle shroud, wherein the collar is in a first angular position relative to the case when the needle shroud is in the first extended position and the carrier is in the first axial position, wherein the collar rotates to a second angular position relative to the case and translates proximally relative to the case when the needle shroud moves from the first extended position to the retracted position, wherein the collar translates distally relative to the case when the needle shroud is in the retracted position and the carrier moves from the first axial position to the second axial position, wherein the boss (8.4) disengages the opening (12.1) and abuts the case when the carrier is in the second axial position, and wherein the plunger translates axially relative to the carrier under the force of the drive spring advancing the carrier from the second axial position to a third axial position relative to the case, wherein the collar rotates to a third angular position relative to the case and translates with the needle shroud distally relative to the case when the carrier is in the third axial position, wherein the carrier includes a compliant beam (8.2) adapted to engage the rib (2.3) when the carrier is in the first and second axial positions. a case; a needle shroud telescopically coupled to the case and movable between a first extended position, a retracted position and a locked second extended position; a carrier slidably arranged in the case and adapted to hold a medicament container, the carrier movable from a first axial position to a second axial position relative to the case; a collar slidably disposed in the case, the collar coupled to the carrier; and a trigger button operably coupled to the carrier, wherein the carrier abuts a rib (2.3) in the first axial position and the needle shroud is in the first extended position and disengages the rib (2.3) when the needle shroud is in the retracted position and the trigger button is pressed to advance the carrier to the second axial position, the autoinjector further comprising a control spring biasing the collar in a distal direction relative to the case, a plunger slidably coupled to the carrier; and a drive spring biasing the plunger relative to the carrier, characterized in that the case includes said rib (2.3),