Fob/Card/RFID
A card, fob or tag presented to the reader. Faster than a code, harder to share casually than a PIN, and immediately revocable if it goes missing. The important technical question is the frequency and format, because that determines credential compatibility and how easily a card can be cloned.
Frequencies and formats
Not all RFID is equivalent. A 125 kHz fob can be copied at a kiosk in minutes. If the door protects anything meaningful, specify an encrypted 13.56 MHz format and avoid handing out cards that can be duplicated without your knowledge.
Practical considerations
- Credential capacity - how many cards or fobs the lock holds, and whether they can be named individually.
- Revocation - removing a lost card may require physical access to the lock unless a gateway is fitted.
- Read distance - typically a few centimetres. Wallets with multiple cards can interfere.
- Credential form - cards, keyrings fobs, adhesive tags and wristbands. Match the form to the user group.
- Sharing spares - order additional credentials with the lock, since matching them later is not always straightforward.
Where cards and fobs work best
- Commercial and staff doors, where credentials must be issued and withdrawn on employment changes
- Tenanted and multi-unit buildings, where each occupant needs individual access
- Short-stay properties, where a fob is handed over and revoked at checkout
- Gyms, clubs and shared facilities with rotating membership
- Users who find keypads or fingerprint readers difficult
Related categories
RFID Fobs, Tags and Cards · PIN Code Smart Locks · Fingerprint Smart Locks · Internal Doors
Common questions
Can I use my existing building access card?
Only if the lock reads the same frequency and format, and the card is not encrypted with keys you do not hold. Bring the card in and we can check the format before you buy.
Only if the lock reads the same frequency and format, and the card is not encrypted with keys you do not hold. Bring the card in and we can check the format before you buy.
What happens if someone loses a fob?
Delete that credential from the lock. On a Bluetooth-only lock you will need to be at the door to do it; with a gateway it can be done remotely. Until it is deleted, the fob still works.
Delete that credential from the lock. On a Bluetooth-only lock you will need to be at the door to do it; with a gateway it can be done remotely. Until it is deleted, the fob still works.
Are RFID fobs secure?
It depends entirely on the format. Low-frequency 125 kHz credentials are trivially cloned. Encrypted 13.56 MHz formats are substantially stronger. The lock listing should state which it uses.
It depends entirely on the format. Low-frequency 125 kHz credentials are trivially cloned. Encrypted 13.56 MHz formats are substantially stronger. The lock listing should state which it uses.
How many spare fobs should I order?
Enough for every user plus two. Matching additional credentials later is straightforward on some platforms and awkward on others, so it is worth over-ordering at the outset.
Enough for every user plus two. Matching additional credentials later is straightforward on some platforms and awkward on others, so it is worth over-ordering at the outset.
Guides and reference
Ch 03 - RFID access · Ch 15 - App platforms · Platform choice for commercial sites