The different access control technologies: cards, biometrics, codes and smartphones

Card-based access control offers a practical and scalable solution for businesses of all sizes. Cards are generally straightforward to issue and manage, making them particularly suitable for organisations with large numbers of employees or multiple access points.

Access permissions can be assigned, updated or revoked centrally, allowing administrators to respond quickly when employees join or leave the business, change roles or report a lost card.

Cards are also durable and convenient for everyday use, while the availability of different credential technologies allows businesses to select a solution that meets their security and operational requirements.

One of the main limitations is that physical cards can be lost, stolen or shared, potentially allowing someone other than the authorised holder to gain access.

Older or less secure card technologies may also be vulnerable to cloning or unauthorised duplication. Modern systems using encrypted credentials and secure authentication can significantly reduce these risks.

Additional security measures, such as combining a card with a PIN or biometric verification, may be appropriate for areas requiring higher levels of protection.

Biometric access control uses an individual's distinctive physical characteristics to verify their identity and determine whether they are authorised to enter a building or restricted area.

Several technologies are available, including fingerprint recognition, facial recognition, iris scanning and vein recognition, which analyses the unique patterns of blood vessels within a finger or hand.

Unlike traditional cards or PIN codes, biometric credentials are linked to the individual rather than something they carry or remember. This can provide an additional level of security by reducing the risks associated with lost, stolen or shared credentials.

Biometric access control offers an additional level of identity assurance by linking access credentials to an individual's physical characteristics.

Unlike cards or PIN codes, biometric credentials cannot simply be lent or shared with another person. Users also benefit from not having to carry a physical card or remember an access code.

When appropriately implemented, biometric systems can strengthen access security and improve the reliability of access records, making them particularly useful for areas requiring enhanced identity verification.

Biometric systems require careful consideration of privacy, data protection and user acceptance.

Under the UK General Data Protection Regulation (UK GDPR), biometric data processed for the purpose of uniquely identifying an individual is classified as special category personal data. Organisations must establish an appropriate lawful basis and an additional condition for processing this information, alongside implementing suitable security safeguards.

The necessity and proportionality of biometric access control must also be considered, particularly in workplaces where employees may have concerns about how their personal data is collected, stored and used.

Biometric systems are not infallible. Recognition accuracy can be affected by environmental conditions, equipment performance and individual characteristics, while appropriate measures are needed to protect against spoofing and unauthorised access.

The main limitation of keypad access control is the potential for PIN codes to be shared, observed or disclosed to unauthorised individuals.

Where a single code is shared between multiple users, it can also be difficult to establish who has accessed a particular area, reducing individual accountability and the usefulness of access records.

PINs should be changed promptly if they are suspected of being compromised, while appropriate code management and access permissions can help reduce security risks.

Keypad access control is particularly suitable for smaller premises, individual doors and areas where straightforward access management is required.

It can also be used alongside cards or biometric verification as part of a multi-factor authentication system, providing an additional layer of security for more sensitive areas.

Smartphone access control allows authorised users to enter buildings and restricted areas using digital credentials stored on their mobile devices.

These systems typically use Bluetooth Low Energy (BLE) or Near Field Communication (NFC) to communicate with compatible access control readers. Depending on the technology, credentials may be managed through a dedicated mobile application or a supported digital wallet.

One of the main advantages is convenience. Employees can use a device they already carry, reducing the need for separate physical access cards.

Compatible systems also allow administrators to issue, update or revoke digital credentials remotely, simplifying access management across one or multiple locations.

Temporary mobile credentials can be particularly useful for visitors, contractors and temporary staff, allowing access permissions to be restricted to specified areas and time periods.

Smartphone access control depends on users having compatible mobile devices and functioning digital credentials. Battery life, device condition and compatibility can affect access, although some systems support limited operation when a phone's battery is depleted.

Lost, stolen or compromised smartphones may also present security risks, making secure credential management and the ability to revoke access promptly important considerations.

Organisations must also consider users who do not have a suitable smartphone or who may be unable or unwilling to use a personal device for workplace access.

Providing alternative access methods, such as cards or PIN codes, can help ensure the system remains practical and accessible for employees, visitors and contractors.

The table below compares card, biometric, keypad and smartphone access control across key considerations, including security, installation and ongoing costs, ease of use, administration and typical applications.

It provides an overview of the advantages and limitations of each technology to help businesses identify which solutions may be most appropriate for their premises and operational requirements.

Selecting the right access control system involves more than comparing technologies and costs. The most appropriate solution depends on the security risks, operational requirements and characteristics of each organisation.

Before making a decision, businesses should consider several key questions:

• Security requirements: Which areas require restricted access, and are different levels of security needed across the premises?
• User management: How many employees, visitors and contractors will require access, and how frequently will permissions need to change?
• Costs: What are the initial installation costs and ongoing requirements for administration, maintenance and support?
• System integration: Does the access control system need to work alongside existing CCTV, intruder alarms, fire safety systems or HR software?
• Flexibility: Can the system accommodate temporary access, changing working patterns and future business growth?

The chosen solution should also support safe evacuation and comply with applicable fire safety and data protection requirements.

Conclusion: Choosing the Right Access Control Solution

No single access control technology is suitable for every business. Cards, biometrics, PIN codes and smartphones each offer different advantages, and the most appropriate choice depends on an organisation's security requirements, operational needs, building layout and budget.

For many businesses, combining different access control technologies can provide a practical and flexible solution. For example, card or smartphone access may be suitable for general entry points, while more sensitive areas may benefit from additional verification.

Multi-factor authentication, such as requiring both an access card and a PIN, can provide an additional layer of security where stronger identity verification is needed.

Ultimately, an effective access control strategy should balance security, convenience and ease of administration, while allowing the system to adapt as business requirements change.

No single access control technology is inherently the most secure. The level of protection depends on factors such as credential security, system configuration, access permissions and how the technology is managed.

Biometric systems can provide strong identity verification, while modern encrypted cards and securely managed smartphone credentials can also offer high levels of security.

For higher-risk or restricted areas, multi-factor authentication, such as combining an access card with a PIN, can provide an additional layer of protection.

Yes, some access cards can be cloned, particularly older technologies that rely on fixed identifiers without strong encryption.

Modern smart cards, such as MIFARE DESFire EV2 and EV3, support advanced encryption and authentication features that can significantly reduce the risk of unauthorised duplication.

However, overall security also depends on how the cards are configured, how encryption keys are managed and whether the access control system uses secure authentication rather than relying solely on a card's identifier.

Choosing an appropriately secured card technology is therefore an important part of protecting against credential cloning.

Yes, biometric access control can be used legally in UK workplaces, provided the organisation complies with UK data protection legislation.

Where biometric data is processed to uniquely identify individuals, organisations must establish a lawful basis under Article 6 of the UK GDPR and meet an additional condition under Article 9 for processing special category personal data.

A Data Protection Impact Assessment (DPIA) will generally be required to assess privacy risks, necessity and proportionality. Appropriate safeguards must also be implemented to protect biometric information, including secure storage, access controls and data retention arrangements.

Yes. Different access control technologies can be combined to meet varying security requirements across a building or site.

For areas requiring enhanced protection, multi-factor authentication can provide an additional layer of security by requiring users to verify their identity using two or more different factors.

For example, combining an access card with a PIN, or a card with fingerprint verification, can help reduce the risk of unauthorised access.

The most appropriate combination depends on the security risks, operational requirements and needs of the organisation.

Visitor access can be managed using temporary access cards, time-limited PIN codes, mobile credentials or QR codes, depending on the capabilities of the access control system.

Access permissions can be restricted to specific areas and time periods, helping businesses manage visitors, contractors and temporary staff without issuing permanent credentials.

The most appropriate approach depends on visitor numbers, security requirements and whether additional measures, such as identity verification, visitor registration or escorted access, are necessary.