How do Proximity Cards Work?

Grey Clock

How do Proximity Cards Work?

A proximity card or prox card is a “contactless” smart card, which means it is read without the need to physically touch or contact a reader device. Sealed inside the prox card is an antenna, capacitor and a Radio Frequency Identification (RFID) chip which stores an ID number. The reader device, such as a time clock, also has an antenna which continuously transmits a short range radio frequency field. When the card is held within close proximity (1-3 inches) of the reader unit, the chip transmits the ID number to the reader device. The reader then performs a programmed function with the ID number, such as clocking an employee In or Out of work. The reader usually confirms communication using audio and/or visuals, such as an audible beep or an ID number displayed on a screen.

User Convenience.

Proximity cards are quicker and easier than swipe style cards since they only require the user to simply hold them within close range (1 to 3 inches) of the reader unit. Magnetic stripe cards, or swipe cards require the user to hold the card in a specific direction when making physical contact with the reader.


Because proximity cards have no openings or exposed components such as a magnetic strip, the chance for damage or vandalism is greatly diminished. Proximity time and attendance systems are preferred over swipe cards for locations where dirt, dust and debris are prevalent and may scratch the magnetic stripe.

Benefits of Proximity Cards

Proximity time and attendance is a quick, convenient clock in method

Proximity time clocks confirm employee punch with audible beep and ID number display on screen

Proximity cards are virtually damage resistant