RFID cards, also known as contactless cards or smart cards, are used in multiple applications worldwide. Chances are, you use one when you pay for your shopping, tap onto the bus reader or gain access to the office or your gym.
RFID cards don’t need physical contact with a reader to work; you simply present the card within the reader’s operating range. Some RFID cards display the familiar contactless symbol, but many access-control cards don’t, so you can’t reliably identify the technology from appearance alone.
RFID smart cards have become a mainstay of many industries; identity management, access control, transportation, finance and payments – you name it, there’s an RFID card for it.
They’re also widely used for branded solutions such as custom printed RFID cards in workplaces and venues, and even in RFID wristbands for hotels to simplify guest access.
Trying to work out which RFID card you need?
If you already have an access control, membership or identification system, your RFID cards need to match the system you use. Choose the next step that best fits what you need.
What exactly is an RFID card?
RFID cards contain a chip within them that is embedded and not visible to the naked eye.
RFID stands for Radio Frequency Identification. Basically it means that data is transferred digitally (sent and received) from the chip contained within the card through the use of non-contact radio waves.
The level of security depends on the RFID technology and the system it is used with. Some smart cards use authentication keys and encryption to protect stored data, while simpler proximity cards may mainly transmit a unique identifier for the reader or access-control system to recognise.
If the data is transferred effectively, the 'action' is completed - whether that's opening a door, validating your ticket or recording a purchase 'event' on your account.
An antenna is also embedded in the body of the RFID card to allow radio frequencies to transfer between the card and the reader – without this the RFID card is unable to send and receive signals.
How do RFID cards work?
It’s a surprisingly simple process. The RFID card is brought into the electromagnetic field of the reader, which activates the chip and allows it to be read.
Upon activation, a wireless connection is established between the RFID card and the reader to allow the data to transfer.
Energy from the reader activates the embedded chip ➡️ The reader and card communicate ➡️ The card returns its identifier or stored data ➡️ The system decides what should happen next, such as opening a door or validating a ticket.
What information is stored on an RFID card?
It depends on the chip. Some basic proximity cards mainly carry a factory-programmed unique identifier, while smart cards such as MIFARE Classic or DESFire can provide memory for application data, depending on how the system has been configured.
That doesn’t mean a new RFID card will automatically work with your doors, membership system or other software. It may still need to be enrolled or encoded. Read our guide to RFID card programming and enrolment.
How many types of RFID card are there?
More than you’d think – RFID cards are split into low, high and ultra-high frequencies, and each can be active, passive or semi-passive.
Swipe or scroll sideways to compare all five card types.
| What matters | 
MIFARE Classic® 1K
|
MIFARE DESFire® EV2
|
MIFARE Ultralight® EV1
|
EM4200 Proximity
|
NTAG 216
|
|---|---|---|---|---|---|
| Best for | Everyday workplace access, gyms and offices. | Hotels, universities and secure multi-use systems. | Events, tickets and low-cost passes. | Older 125 kHz door systems still in use. | NFC tasks, attractions, interactive experiences. |
| Frequency | 13.56 MHz (HF) | 13.56 MHz (HF) | 13.56 MHz (HF) | 125 kHz (LF) | 13.56 MHz (HF/NFC) |
| Security level | Legacy security; not recommended for higher-security applications | High – supports AES and advanced authentication | Low (short-term use) | Low (basic proximity) | Moderate |
| Typical uses | Door access, staff badges, memberships | Accommodation, cashless systems, student cards | Festival tickets, transport, visitor passes | Legacy access control | Museums, attractions, marketing triggers |
| Memory | 1KB | High capacity | Small | N/A | 888 bytes |
We’ll break down the frequencies first…
- Low Frequency RFID Cards (30 KHz to 300 KHz)
Low frequency cards have both a slower and shorter read rate when compared to high or ultra-high frequencies.
The upside to this is that low frequency RFID cards are far less susceptible to interference due to their longer wavelength.
- High Frequency RFID Cards (3 to 30 MHz)
High frequency cards have a longer read range when compared to low frequency RFID cards – whilst also having higher memory capabilities.
High frequency RFID is moderately sensitive when it comes to interference, passing through most materials apart from water and dense metals.
- Ultra-High Frequency (300 MHz to 3GHz)
Ultra-high frequency RFID cards are the most sensitive to interference – with 20 times the range and speed of high frequency.
When compared to both low and high frequency, the ultra-high data transfer rate makes it ideal for applications that need to read multiple items at once.
Active, Passive and Semi-Passive RFID Cards
Active:
Battery boosts signal strength.
Longer read range.
Passive:
Inactive until radio signal from reader.
Energy from reader activates card.
Semi-Passive:
Battery present but only activates the chip.
Does not transmit its own signal.
RFID cards offer a simple, secure method of communication for many applications, digitally storing data whilst protecting personal information.
Search our RFID Card range.
Not sure what type of access control or RFID card you need for your system? Read our guide. If you are comparing RFID cards with wristbands, here's a quick guide on how RFID wristbands work.
RFID Card FAQs
Common questions about how RFID cards work, their uses, and security.
Understanding RFID
Learn more about how RFID cards work and where they’re used.
What are RFID cards used for?
RFID cards are used for secure access control, cashless payments, public transport passes, and staff ID badges. You’ll also find them in hotels and gyms where guests simply tap to enter or pay.
Are RFID cards safe?
RFID security varies by card technology and system. Higher-security smart cards can use authentication and encryption, while simpler proximity cards offer more basic protection. If security is important, check the specific card technology supported by your system rather than assuming all RFID cards offer the same level of security.
Can I reuse or reprogram an RFID card?
Sometimes. It depends on the card technology and the system you’re using. Some RFID cards have rewritable memory or can be re-enrolled to another user, while others are read-only. For example, EM4200 contains a factory-programmed unique code and is not rewritable.
Do RFID cards need programming?
It depends on what you need the card to do. Access-control cards normally need to be enrolled onto the relevant system, while some applications may also require data to be encoded to the card. Read our guide to RFID card programming and enrolment.
Practical Questions
Everyday RFID queries and how to get the most from your cards.
What’s the difference between RFID and contactless cards?
RFID is the technology behind wireless data transfer. Contactless cards are one type of RFID card, typically used for payments or door access.
Do RFID cards interfere with each other?
Occasionally — if you hold multiple RFID cards together, the reader may struggle to pick the right one. Tap cards individually for the best results.
