Choosing the right access control method can make a significant difference to the security and day-to-day running of a building. Key fobs, PIN codes, access cards and mobile credentials all provide ways to control who can enter, but each works differently and offers its own advantages and limitations.
For UK businesses, property managers and organisations responsible for staff, visitors or tenants, the best option depends on how the premises are used, the level of security required and how access permissions need to be managed. Some buildings benefit from one straightforward method, while others need a combination of technologies.
This guide explains the differences between key fob, PIN, card and mobile access systems, including their costs, security considerations and practical uses. It also explores how to choose a suitable solution with support from an experienced security provider such as William Hale Fire & Security.
Understanding Key Fob, PIN, Card or Mobile Access Systems
Access control systems replace or supplement traditional keys by allowing entry to be managed electronically. Instead of giving every authorised person a physical key that may open several doors, a business can issue individual credentials and decide which areas each person can enter.
The four common options are key fobs, PIN codes, access cards and mobile credentials. Although they all serve the same basic purpose, the way users identify themselves and the way permissions are managed can differ considerably.
How key fob access works
A key fob is a small electronic device, usually attached to a keyring. The user presents it to a compatible reader, which checks the credential and grants access if permission is valid.
Fobs are convenient because they are easy to carry and generally simple to use. They are particularly suitable for workplaces, apartment blocks, staff entrances and buildings where people enter and leave regularly.
If a fob is lost, an administrator can usually deactivate its credential without changing the locks or replacing every user’s device. This is a major advantage over conventional keys.
How PIN access works
A PIN system uses a keypad installed near a door or entry point. Users enter an authorised number to unlock the door.
This can be useful where issuing individual physical credentials would be inconvenient, such as a small office, plant room or shared facility. It also avoids the need for users to carry a fob or card.
However, PIN codes can be shared, observed or passed on to people who should not have access. Regular changes and sensible code management are therefore essential.
How card and mobile access work
Access cards operate in a similar way to fobs but are usually credit-card sized. They can be carried in a wallet, displayed on a lanyard or used as part of an employee identification system.
Mobile access uses a smartphone as the credential. Depending on the system, the phone may communicate with a reader through Bluetooth, NFC or another supported technology.
Mobile credentials can reduce the need to issue physical devices, although users need a compatible phone and must understand how to use the system reliably.
Key Fob, PIN, Card or Mobile Access: Comparing Security
Security is not determined by the type of credential alone. The quality of the access control equipment, the reader technology, system configuration and management procedures all influence how effectively a building is protected.
A well-managed PIN system may be more suitable than a poorly administered card system. Equally, mobile access is not automatically more secure simply because it uses a smartphone.
| Access method | Main security advantage | Main limitation | Typical suitability |
|---|---|---|---|
| Key fob | Individual credentials can be cancelled | Can be lost or lent to someone else | Regular staff and residents |
| PIN code | No physical credential to lose | Codes can be shared or observed | Controlled, lower-risk access points |
| Access card | Individual cards can be assigned and disabled | Cards can be lost, stolen or shared | Offices and larger workplaces |
| Mobile access | Credentials can be managed digitally | Depends on compatible devices and system security | Modern workplaces and managed buildings |
Individual credentials and accountability
One of the most useful features of electronic access control is the ability to assign credentials to individuals. If each employee has their own fob, card or mobile credential, administrators can manage access more accurately than with a single shared door code.
Some systems also record access events, showing when a credential was presented at a reader. This can help with security investigations and operational oversight, although the information must be handled responsibly and in line with applicable data protection requirements.
A shared PIN provides less individual accountability because the system may record the code being used without identifying the person entering it.
Lost, stolen or compromised credentials
Every access method has a potential weakness if a credential falls into the wrong hands.
A lost card or fob should be reported promptly so that its permissions can be removed. A compromised PIN should be changed, with the replacement communicated securely to authorised users.
Mobile credentials introduce additional considerations. Businesses should have a procedure for removing access when an employee leaves, changes role or loses their phone.
The importance of system configuration
A secure credential cannot compensate for poor access permissions. Staff should only be able to enter areas required for their responsibilities, and sensitive rooms should have additional controls where appropriate.
For example, a general office entrance may allow access to all employees, while a server room, records store or plant area may be restricted to specific authorised personnel.
Key Fob Access: A Practical Choice for Everyday Use
Key fobs remain a popular option because they offer a straightforward way to manage entry without requiring users to remember codes or carry a larger access card.
They are compact, easy to attach to a keyring and suitable for frequent use. Once a person has been issued with a fob, entry generally involves presenting it to the reader rather than entering information manually.
Advantages of key fob systems
The main benefit is convenience. Employees and residents can carry a fob alongside their everyday keys, making it easy to use familiar entry points throughout the day.
Fobs can also be individually programmed, depending on the capabilities of the access control system. This means one user could be authorised to enter the main building and staff facilities, while another may only have permission for a specific area.
If someone leaves the organisation, their fob can normally be cancelled without affecting other users.
Limitations to consider
The main drawback is that fobs are physical objects and can be lost, damaged or shared. A user may also forget to bring their fob, creating inconvenience if there is no alternative authorised entry method.
Some older or less sophisticated systems may have limitations in credential security or administration. The technology used by the reader and fob matters, so businesses should not assume all systems provide the same level of protection.
Where key fobs work particularly well
Key fobs are often suitable for:
- Office buildings with regular staff attendance.
- Apartment blocks and communal entrances.
- Staff-only doors in commercial premises.
- Gyms and membership facilities.
- Buildings where users need simple, repeatable access.
For organisations with a stable group of regular users, fobs can provide a useful balance between convenience and manageable administration.
PIN Access: Simple Entry Without Physical Credentials
PIN access is often attractive because it does not require users to carry a separate device. A keypad provides a familiar method of entry, and authorised people can gain access by entering the correct code.
It can be particularly useful for doors where access is occasional rather than continuous. For example, a business might use a keypad for a restricted storage area or a controlled entrance used by a small number of approved people.
Benefits of PIN systems
The most obvious advantage is simplicity. There are no cards or fobs to distribute, collect or replace, which can reduce the administrative burden for smaller premises.
A code can also be changed when access arrangements need to be updated. This may be useful for temporary access, provided the system allows suitable management and the code is changed promptly afterwards.
PIN entry can be used independently or alongside another credential. Some systems support two-factor access, requiring a user to present a card or fob and then enter a PIN.
The risks of shared codes
A PIN is only as secure as the way it is managed. If a code is written on a noticeboard, shared through an unsecured message or given to people who do not need access, the system’s effectiveness is reduced.
There is also a risk that someone may observe a user entering a code. Keypads can show signs of repeated use on particular buttons, and poorly positioned equipment may make it easier for others to watch the entry process.
For this reason, businesses should avoid obvious codes such as simple sequences or easily guessed numbers. Codes should not be shared unnecessarily, and access should be reviewed whenever staff or contractors no longer require it.
When PIN access is suitable
PIN systems can work well for smaller premises, controlled internal doors and areas with limited authorised users. They may also be useful as part of a wider access control arrangement.
For busy entrances with many users, individual credentials are generally easier to manage because access can be assigned and withdrawn without changing a code used by everyone.
Access Cards: Flexible Control for Larger Organisations
Access cards offer many of the same advantages as key fobs, but their larger format can make them more practical in workplaces where identification and building access need to work together.
A card may be issued as part of an employee pass, allowing staff to carry one item for identification and entry. It can also be printed with a photograph or other organisational information, depending on the employer’s requirements.
Why businesses choose access cards
Cards are particularly useful where an organisation has a large number of employees, visitors or contractors. Each card can be associated with a specific user and assigned permissions according to their role.
If an employee changes department, their access rights can be amended without necessarily issuing a completely new card. If they leave, the credential can be disabled.
Some access control systems can also support temporary cards for visitors or contractors. These can be configured to work only for certain doors or periods, helping to prevent unnecessary access after a visit has ended.
Potential disadvantages
Cards are larger than fobs and may be less convenient for people who prefer to carry only a small set of keys. They can also be misplaced, damaged or accidentally left behind.
As with fobs, the technology matters. Organisations should check that cards and readers are compatible and that the chosen credential technology provides an appropriate level of security.
A card that is simply used as a shared pass offers limited accountability. Individual assignment and proper administration are what make the system more effective.
Common applications
Access cards are particularly suitable for:
- Corporate offices and multi-floor buildings.
- Educational and training premises.
- Healthcare and professional facilities.
- Industrial sites with different restricted zones.
- Commercial buildings with regular visitors and contractors.
They are often a strong choice where access needs to be managed across multiple doors and departments.
Mobile Access: Using a Smartphone as Your Credential
Mobile access allows authorised users to unlock doors using a smartphone instead of a physical card or fob. The phone communicates with a compatible reader, and the system checks whether the digital credential has permission to enter.
For organisations already using smartphones for work-related tasks, this can be a convenient addition. It may also simplify the process of issuing credentials to new employees or removing access when someone leaves.
Advantages of mobile credentials
One benefit is that users are less likely to forget a credential if they already carry their phone throughout the day. Digital credentials can also be issued and managed remotely where the system supports this functionality.
Some platforms offer additional administration features, such as assigning access permissions through software and managing credentials without physically collecting a card or fob.
Mobile access may also reduce the need to store and distribute large quantities of physical credentials. This can be useful for organisations with multiple sites or changing staff numbers.
Limitations and practical considerations
Mobile access relies on compatible hardware and software. Not every phone, operating system or reader will support every system, so compatibility should be checked before installation.
Battery life is another consideration. If a phone runs out of charge, the user may be unable to use their mobile credential unless the system provides another approved method of entry.
Businesses should also consider employees who do not have a suitable smartphone or who prefer not to use a personal device for work access. A card or fob alternative may be necessary.
Protecting mobile credentials
Smartphones should be protected with appropriate device security, such as a strong passcode or biometric authentication. Organisations should also understand how credentials are removed if a phone is lost, stolen or replaced.
Mobile access is most effective when it forms part of a properly managed security system rather than being treated as a simple replacement for physical keys.
How Much Does an Access Control System Cost in the UK?
The cost of installing access control depends on the number of doors, the type of readers, the credentials required and the complexity of the building. A straightforward keypad installation will generally cost less than a multi-door system with central management and mobile credentials.
The figures below are indicative UK price guides rather than fixed quotations. Actual costs vary according to site conditions, equipment specification, installation requirements and the level of integration needed.
| Access control option | Typical indicative cost |
|---|---|
| Basic standalone keypad system | £300–£800 |
| Single-door fob or card access system | £500–£1,200 |
| More advanced single-door system | £800–£1,800 |
| Multi-door commercial access control | £2,000–£6,000+ |
| Larger or more complex managed system | £5,000–£15,000+ |
These estimates are broad planning figures. They may not include every requirement, such as additional cabling, door alterations, network work, replacement locking hardware or integration with existing security equipment.
What affects the installation price?
The number of controlled doors is one of the biggest cost factors. Each additional entrance may require a reader, suitable locking equipment, power, cabling and configuration.
The type of door also matters. A standard internal office door may be relatively straightforward, while a heavy external entrance, fire door or specialist access point may require more careful assessment.
Other factors include:
- Whether the system is standalone or centrally managed.
- The number of users and credentials required.
- The type and security level of readers.
- Whether software or a management server is needed.
- Integration with existing alarms or other security systems.
- The amount of installation work required.
Why the cheapest quotation may not offer the best value
A low initial price can be appealing, but access control is a security system that needs to work reliably over time. Poorly selected equipment, inadequate installation or limited administration features may create problems that cost more to resolve later.
A professional quotation should explain the proposed equipment, the number of doors covered, the credential options, installation work and any ongoing costs. Better-quality systems may have a higher initial price because of their equipment specification, reliability, security features and the expertise required to install and configure them properly.
Choosing the Right Access Control Method for Your Building
There is no single access method that suits every property. The right decision depends on the number of users, how frequently they enter, the sensitivity of the areas being protected and how much administration the organisation needs.
For some premises, one credential type will be sufficient. Others may benefit from a mixed arrangement, such as cards for staff, temporary PIN access for a particular facility and mobile credentials for selected users.
Consider the number and type of users
A small office with a handful of regular employees may find a keypad or fob system perfectly practical. A larger organisation with several departments and different access requirements is more likely to benefit from individual cards or mobile credentials.
Think about how often users change. A building with frequent contractors, temporary staff or visiting professionals needs a system that makes it straightforward to issue and cancel access.
Assess the security requirements of each area
Not every door needs the same level of protection. A reception entrance may have different requirements from a stockroom, communications room or confidential records area.
Consider whether users need access at particular times, whether entry should be recorded and whether sensitive areas require an additional authentication step.
A professional site assessment can help identify which doors need electronic control and what type of locking and reader equipment is appropriate.
Plan for emergencies and building safety
Access control must work alongside the building’s wider safety arrangements. Door locking equipment and access permissions need to be suitable for the door’s purpose, particularly where the door forms part of an escape route.
Fire safety requirements should be considered before choosing or installing locking arrangements. An access control system must not prevent people from escaping during an emergency, and any necessary release arrangements should be designed and tested appropriately.
The installation should also be coordinated with existing fire alarm and door hardware requirements where relevant.
Compare the main options
| Requirement | Suitable option to consider |
|---|---|
| Small number of regular users | Key fob or PIN |
| Large workforce | Access cards |
| Users who regularly carry smartphones | Mobile credentials |
| Temporary or changing access | Individually managed cards, fobs or mobile credentials |
| Areas requiring stronger authentication | Card or fob combined with PIN |
| Shared facilities with limited users | Carefully managed PIN access |
These are starting points rather than strict rules. A system’s capabilities and the risks associated with the premises should guide the final choice.
Questions to ask an installer
Before agreeing to an installation, ask how the system will be administered, what happens when a credential is lost and how quickly access permissions can be changed.
You should also establish whether the equipment can support future expansion. A system that meets today’s requirements may become restrictive if the business adds more doors, takes on additional staff or changes the way the building operates.
Frequently Asked Questions
Is a key fob more secure than a PIN code?
A key fob can offer better individual accountability because each user can be assigned a separate credential. A PIN code may be shared without the administrator knowing who has used it. However, security depends on the technology, configuration and management of the whole system.
Can I use key fobs and access cards on the same system?
Yes, some access control systems support both fobs and cards, provided the readers are compatible with the credentials. This can be useful for organisations that want to give different users a choice of physical credential while managing access through one system.
What happens if an employee loses their access card or fob?
The lost credential should be reported and disabled as soon as possible. An administrator can usually remove its permissions without changing the locks or affecting other users. A replacement can then be issued and programmed with the appropriate access rights.
Does mobile access work if my phone has no internet connection?
It can, depending on the technology and system design. Some mobile credentials communicate directly with the door reader using Bluetooth or NFC, so a live internet connection may not be needed at the point of entry. The specific system should be checked before installation.
Can access control systems restrict entry by time of day?
Yes, many professionally managed systems allow permissions to be restricted by time and day. For example, staff may be authorised to enter during normal working hours, while selected managers have additional access outside those periods. The available scheduling features depend on the system.
Is a PIN keypad suitable for a commercial building?
A PIN keypad can be suitable for certain commercial entrances and restricted areas, particularly where the number of authorised users is small. For larger workplaces, individual credentials may provide better accountability and easier administration. The security requirements of each door should determine the choice.
Can access control be added to an existing door?
In many cases, yes, although the door, frame, lock and surrounding hardware must be assessed first. Some doors may need additional electrical or mechanical work, and fire doors require particular care to ensure that any alterations remain suitable for their safety function.
How often should access permissions be reviewed?
Businesses should review permissions whenever someone changes role, leaves the organisation or no longer needs access to a particular area. A scheduled review is also sensible, particularly in larger buildings where staff, contractors and visitor arrangements change regularly.
Can an access control system work with a fire alarm?
Yes, suitable systems can be integrated with fire alarm arrangements so that doors operate in accordance with the building’s emergency safety requirements. The design must ensure that people can escape safely and that any required door release functions work correctly during an emergency. Installation and testing should be carried out by competent professionals.
Is mobile access worth the extra cost?
Mobile access can be worthwhile for organisations that value digital credential management, remote administration and reduced reliance on physical cards or fobs. It may be less suitable where users have incompatible devices or prefer not to use personal phones. The benefits should be weighed against equipment, software and support costs.