How Door Access Control Systems Work (Simple Breakdown for Businesses)
Controlling who enters your building is one of the most basic but important parts of business security. That’s why door access control systems are now the go-to solution for modern businesses, replacing old-fashioned locks and keys.
But how do they actually work?
In this guide, we’ll explain how door access systems function, what equipment is involved, and the options available – without the tech jargon.
What is a Door Access Control System?
A door access control system is an electronic system that lets you control and monitor who can unlock specific doors or entry points in a building.
Instead of using keys, people use things like:
Key fobs or cards
PIN codes
Mobile phone apps
Fingerprints or facial recognition
You set the rules for who can enter, where, and when – giving you total control over building access.
How the System Works – Step-by-Step
Let’s say someone walks up to your office door. Here’s what happens:
They present their credential (fob, card, phone, PIN, etc.) to a reader.
The reader sends the data to a control panel (also called the access controller).
The controller checks the database:
Is this person allowed to enter this door at this time?If yes, it sends a signal to unlock the door.
If no, access is denied and it can trigger an alert or log the attempt.
The entire process takes less than a second.
Main Components of a Door Access System
1. Access Credentials
This is what people use to “unlock” the door:
Proximity key fobs/cards
Mobile phone with NFC/Bluetooth
PIN codes (less secure but useful)
Biometric data (fingerprint, facial recognition)
Some systems let you use multiple types together — like fob + PIN for extra security.
2. Access Readers
Mounted on or near doors, these devices scan the credentials. Types include:
RFID readers (for cards/fobs)
Keypads (for PINs)
Biometric readers (fingerprint, face)
Mobile phone readers
3. Electric Locks
When access is granted, these unlock the door:
Maglocks (magnetic locks) – Common for glass doors
Electric strikes – Often used with standard doors
Motorised locks – More advanced, often used in secure areas
4. Access Control Panel (Controller)
Verifies credentials
Stores user permissions
Logs all access attempts
Controls the electric lock
5. Access Management Software
Where admins manage users, permissions, and schedules. Features often include:
Add/remove users
Create access groups (e.g., staff, managers, visitors)
Set door open times
View access logs
Trigger lockdowns or alarms
Local vs Cloud-Based Systems
Local (On-Premise) Systems
Software is hosted on a server or PC onsite
Offers full control, but needs local management
Example: Paxton Net2
Cloud-Based-Systems
Managed via a web dashboard
No onsite server required
Ideal for businesses with multiple locations or remote management needs
Where Door Access Control is Used
Anywhere security and control is important:
Offices – Separate staff, admin, and client access
Warehouses – Restrict sensitive stock areas
Healthcare – Protect patient records or medical supplies
Schools – Lock down buildings quickly when needed
Shared offices or apartment blocks – Manage multiple users easily
Extra Features You Can Add
Modern access control systems often include:
Door status monitoring – Alerts if a door is forced or left open
Time-based access – Only allow access during business hours
Temporary access – For contractors or visitors
Integration with CCTV or alarms – Boost your overall security setup
Common Problems
Fob/card not working? → It may have been deactivated or expired
Door won’t unlock? → Power supply or lock fault
System crash? → Check controller power or software connectivity
Tip: Choose a reputable installer who provides ongoing support and maintenance.
Need a Professional Installer?
A properly installed system is key to avoiding future issues. Our team at SecureEntry has installed door access systems across a wide range of sectors, including:
Offices
Industrial units
Schools and nurseries
Retail premises
We’re certified Paxton Net2 installers and offer free site surveys and clear quotes with no pressure.
Enquire here if you would like more information about our access control system installation at your site.