Described herein are systems and methods for commissioning access control devices. In overview, a carrier substrate such as a smartcard is used to commission a plurality of access control devices. Measures are implemented such that the individual access control devices are uniquely commissioned. That is, no two devices apply identical commissioning data, hi some embodiments this is achieved by, as part of the commissioning process at a given access control device, modifying one or more aspects of the data carried by the carrier substrate.