A medicament delivery device is presented having a housing that is arranged to accommodate a medicament container, a drive unit operably arranged to act on the medicament container upon activation, an activation mechanism operably arranged to be operated by a user, an activation preventing mechanism operably arranged to prevent the activation mechanism to be activated, an usage management module arranged to be operated by a user, which usage management module is designed as an attachable unit to the medicament delivery device. First keying elements are arranged on the device and on the usage management module designed to interact with each other when attaching said usage management module, such as to cause a deactivation of the activation preventing mechanism to allow operation of the activation mechanism. The usage management module can include a monitoring circuit arranged to monitor the use of the medicament delivery device.
