Access control systems rely on unique keys for each individual person who uses the space. When you’re setting up the system, each employee or user is assigned a badge, which allows them the level of access that has been predetermined for them. In order for this to work, each one needs a card number, or a unique ID number assigned to every cardholder’s badge. Because each badge is specific, every single person in the system reads as a different unit, making security much easier.
Card numbers are defined in the Badge form of the Cardholders folder. Depending upon your space’s software configuration, a badge's card number can be manually decided by a user or automatically assigned by the system. For smaller spaces, it makes sense to let everyone choose their own card number, but larger companies or corporations should consider letting the system set them to avoid headaches down the line.