How To Identify RFID Card Reader

You ordered new key fobs or RFID cards and now they won't work with the RFID card reader.  This is usually the result of buying the wrong type of card.  Cards operate in either 125Khz proximity or 13.56Mhz Mifare.  It's usually a mismatch between the card and the reader.

You can look at the back of the RFID card reader to determine the frequency.  It will be marked with either ID or IC.

• ID = 125Khz Proximity
• IC = 13.56Mhz Mifare

One other note: Proximity key fobs and cards usually have the card number printed on them.  Mifare key fobs and cards usually do not have the card number printed.

If you have an Android phone, there are many different apps that can scan your card to tell you exactly what it is.  Just look for NFC (Near Field Communication) on the app store.