What Information Is Stored in an Access Control Card?
Access cards have become an essential part of modern physical security, helping organizations control who can enter buildings, secure sensitive areas, and simplify everyday operations. From office buildings and healthcare facilities to schools, government agencies, and industrial sites, today's credentials can do much more than unlock a door.
Depending on the type of credential and access control system you use, an access card can be programmed with a variety of information that enhances both security and convenience.
Unique Card Identification Number (UID)
Every access card contains a unique identification number (UID), which serves as the credential's digital identity. When a card is presented to a reader, the access control system compares the UID to its database to determine whether the user is authorized.
This information helps the system identify:
The cardholder
Which doors they can access
What days and times access is permitted
Whether the credential is active or inactive
For many organizations, this unique identifier is the foundation of their access control system.
Cardholder Information
While most employee or visitor details are stored within the access control software, certain smart card technologies can also securely store information directly on the credential.
Depending on your organization's needs, this may include:
Employee or contractor ID number
Student identification number
Department or job title
Credential expiration date
Membership or account information
This allows the credential to become part of a larger identity management solution.
Access Permissions
Modern smart cards can also contain encrypted security information that helps verify the credential's authenticity before access is granted.
These security features may include:
Encrypted authentication keys
Digital security certificates
Application-specific credentials
Secure encryption data
These protections make it significantly more difficult to clone or duplicate authorized credentials, providing an additional layer of security for high-risk facilities.
Facility or Site Codes
Many organizations program facility codes into their credentials. These codes identify which organization issued the card and help prevent unauthorized credentials from being accepted by the system.
Facility codes are especially valuable for:
Multi-building campuses
Shared commercial properties
Government facilities
Multi-tenant office buildings
Multiple Applications on One Card
Today's access cards often serve many purposes beyond opening doors. A single credential can securely support multiple applications, reducing the need for employees to carry several different cards.
Common applications include:
Building access
Time and attendance tracking
Secure print release
Computer or workstation login
Cafeteria or vending payments
Parking garage access
Equipment or asset checkout
By combining these functions into one credential, organizations can improve both efficiency and user experience.
Biometric Authentication Data
For organizations with advanced security requirements, smart cards can work alongside biometric systems to strengthen identity verification.
Rather than storing actual fingerprint or facial images, these cards typically contain encrypted biometric templates used during authentication.
This additional layer of verification is commonly used in:
Government facilities
Critical infrastructure
Healthcare environments
Data centers
Research laboratories
Credential Lifecycle Management
Access cards can also be programmed with information that helps administrators manage credentials throughout their lifecycle.
Examples include:
Activation dates
Expiration dates
Temporary access permissions
Access level assignments
Security validation data
These features make it easy to issue temporary badges, revoke lost credentials, or update employee access as roles change.
Choosing the Right Credential Technology
The amount of information an access card can store depends on the credential technology being used.
Basic proximity cards typically contain only a unique identification number, making them ideal for straightforward door access applications. Smart cards, on the other hand, offer greater storage capacity, stronger encryption, and support for multiple applications, making them well suited for organizations with more complex security requirements.
Working with an experienced security integrator can help ensure you choose a credential technology that meets your current needs while providing flexibility for future growth.
Capture Technologies Can Help
An access card is much more than a piece of plastic—it's a critical component of your organization's overall security strategy. The information programmed into each credential determines who can access your facilities, when they can enter, and what additional systems they can use.
Whether you're implementing a new access control system, upgrading outdated credentials, or expanding to multiple locations, Capture Technologies can help you design a secure, scalable solution tailored to your organization.
Contact us today to learn more about access cards, credential technologies, and integrated access control solutions that protect your people, facilities, and assets.