Mobile access control lets people open doors with a smartphone or smartwatch instead of a plastic card: the phone holds a digital credential and presents it to a reader over Bluetooth Low Energy (BLE), near field communication (NFC), or ultra-wideband (UWB). The door hardware still decides, and the management software still grants and revokes rights. What changes is the credential. If you are new to the pieces, our overview of access control explains readers, controllers, and the monitoring layer that sits above them.
Key takeaways
- A mobile credential is a digital key stored on a phone and delivered by the management software, which can issue or revoke it remotely in seconds.
- 3 radio technologies carry it: NFC (read range of a few centimeters), BLE (about 10 meters in open space, tuned lower at the door), and UWB (centimeter-level distance measurement).
- Readers must be mobile-ready. Many 125 kHz proximity readers are not, and 13.56 MHz readers with BLE and NFC are.
- A phone credential proves a device was presented, not that only 1 person entered. Tailgating still needs a camera-based check.
- Plan a fallback for a dead battery or a lost phone before you remove cards.
How Does Mobile Access Control Work?
Mobile access control works in 4 steps: the administrator enrolls a user, the platform sends a digital credential to the user’s phone app or wallet, the phone presents it to the reader at the door, and the controller checks it against the rules and unlocks or refuses.
Step 1: Enrollment and delivery
The administrator adds a person in the management software and assigns door groups and schedules. The user receives an invitation, installs the vendor app, or adds the credential to a phone wallet. Some platforms support wallet-based credentials on both Apple and Google devices, so a person can tap without opening an app.
Step 2: Presentation at the reader
The reader detects the phone. With NFC the user taps within a few centimeters. With BLE the reader can detect the phone from a longer distance, and the vendor decides the distance at which a door will respond. UWB adds precise ranging, which helps a door react only when the person is actually at it.
Step 3: Decision at the controller
As with a card, the controller makes the decision. It checks the credential against its stored rules and drives the lock relay. Communication from reader to controller still runs over a wired protocol, either legacy Wiegand 26-bit or the encrypted, bidirectional OSDP v2.
Step 4: Logging
Each grant and denial is logged with the time and door, and reaches the management software. This is the same audit trail a card system produces, now tied to a specific phone and user.
Mobile Credentials vs Cards vs Fobs
| Factor | Mobile | Smart card (13.56 MHz) | Proximity card (125 kHz) |
|---|---|---|---|
| Issue or revoke | Remote, in seconds | Physical handover | Physical handover |
| Cloning risk | Low, credential is bound to the device | Low with modern formats | High, easy to copy |
| Lost item | Phone is noticed fast and can be locked | May go unnoticed for days | May go unnoticed for days |
| Needs power | Yes, battery | No | No |
| Visitor use | Time-limited link | Temporary card | Temporary card |
| Reader requirement | BLE and NFC capable | 13.56 MHz reader | 125 kHz reader |
Cards still have a place. They need no battery and work for people who do not carry a smartphone. Many sites run both for a transition period. Our guide to the key card entry system explains the card side in detail.
What Should You Check Before Choosing Mobile Access Control?
Reader compatibility
Check whether your current readers support BLE and NFC. If they only read 125 kHz proximity cards, they will need replacement. When you replace them, choose OSDP v2 readers so the link to the controller is encrypted and supervised.
Offline behavior
Ask what happens when the phone has no signal, and when the controller loses its network. A well-designed system stores credentials on the phone and rules on the controller, so a door still opens without internet. Our guide to cloud based access control lists the outage questions to ask.
Phone security
Require a device passcode or biometric unlock on the phone, support remote revocation, and ask how the vendor protects the credential inside the phone. Credentials stored in the phone’s secure area are harder to extract than those in an ordinary app file.
Privacy and consent
Employees are carrying their own devices. Decide what the system will log, tell staff what is collected, and keep location data out unless there is a clear reason.
Fallback plan
Keep a process for a dead battery, a lost phone, or a person without a smartphone: a temporary card, a PIN at selected doors, or a front-desk override.
Mobile Credentials Do Not Count Heads
Switching from cards to phones does not change one fact. The door reads a credential, not a person. When someone holds the door for a colleague, the log shows 1 entry while 2 people enter. This is tailgating, and a phone does not prevent it.
Argu closes that gap on the cameras that already cover the entrance. An agent counts how many people pass after each credential read, whether it came from a card, a PIN, or a phone, and alerts only when the count breaks the rule. The alert names the door and the time and links to the original access record. It reads standard 1080p to 4K feeds at 15 to 30 frames per second and works with the reader and controller you already own. For more on how the door hardware fits together, see our door access control system guide, or compare options in building access control.
Frequently Asked Questions
What is mobile access control?
It is an access control method in which a smartphone or smartwatch stores a digital credential and presents it to a reader to open a door. The management platform issues and revokes the credential remotely.
Is mobile access control secure?
It can be more secure than a basic proximity card, because the credential is tied to a device that is protected by a passcode or biometric unlock and can be revoked immediately. The reader-to-controller link should still use an encrypted protocol such as OSDP v2.
Do doors work if my phone has no internet?
Usually yes. The credential is stored on the phone and the controller holds the rules, so the phone only needs to talk to the reader over BLE or NFC.
Can I use my existing card readers?
Only if they support mobile credentials. Many older 125 kHz proximity readers do not, while newer 13.56 MHz readers with BLE and NFC do.
What is the difference between NFC, BLE, and UWB?
NFC works at a few centimeters, BLE works at longer range, and UWB measures distance precisely so a door can respond only when the person is close.
Does mobile access control stop tailgating?
No. A phone is still a credential. Camera-based tailgating detection is the usual way to catch a second person entering on one read.
Mobile access control makes issuing and revoking keys faster. It does not show who walks in behind the phone holder. Argu watches that moment on the cameras you already have, whichever credential you choose. Talk to Argu about the doors where one credential must mean one person.
Last updated: October 2026
