Card access systems: How they work, key card options, and who needs them

Card access systems: How they work, key card options, and who needs them

man swiping card at card access reader on a brick background

Access control and card access systems are the modern version of an old-fashioned lock and key. They are more effective and efficient at securing buildings and making sure the right people have access to the right places at the right time. It allows you to identify who is in your building, control access to highly secure areas, and provide a safe environment for employees and visitors.

How it works

Proximity card readers work by carrying power and data between the access control system panel and the reader. The reader emits an electromagnetic field so when a proximity card is brought within the field the card is able to transmit its number to the reader through electronic circuits. If the card number is valid and approved the door unlocks for a short period of time. You can program proximity cards to open specific doors, stop working during certain hours, and deactivate cards to deny employees further access. Card access gives you flexibility and security that traditional locks and keys do not.

Types of proximity card readers

Some access control systems still use a swipe card system that utilizes a magnetic strip to unlock a door, but we suggest moving towards proximity readers because of their durability, functionality, and range of card forms. Proximity card readers come in a variety of forms ranging from key fobs to micro tags.

Key Fobs     


  • Proximity key fobs incorporate 125 kHz or 13.65 MHz reader technology for door access
  • Small enough to place on a key ring or lanyard for convenience
  • Highly durable for frequent use

Key Cards     

  • Proximity cards can be printed on with a custom logo or photo identification
  • Perfect for one-time visitor use
  • Vertical or horizontal punch capability to be attached to a lanyard

Micro Tags

  • MicroProx tags can easily convert an existing photo ID to a proximity card by attaching the adhesive-backed tag to a nonmetallic card or device
  • Roughly the size of a coin
  • It is compatible with all HID proximity card readers and can be programmed in any HID proximity format

Best uses for key cards & card readers


Using access control allows both employers and employees to feel safe in their workplace. Employers are able to manage who has the ability to get in the building and can easily monitor the system. Employees are given access to different parts of the building with a card access key specific to them. Rather than carrying around multiple keys to different locked parts of a single building, employees can use their key fob or ID badge to quickly and safely enter a building.

Proximity cards are perfect for employees who need to have an ID on them at all times. Some HID proximity cards come with the ability to be printed to, easily turning them into an ID card. This way the employee can have their badge attached to a lanyard or in their wallet while moving through the building for ease of use and accessibility.

Other employees prefer to have proximity key fobs as they are very durable and small enough to fit on a key-chain. These are convenient for employees who don’t need to move around much, and only need to get in and out of the building and prefer not to carry around an ID card.


Many facilities still use a handwritten paper log to check visitors in and out of the building. While this method is quick and easy, it provides essentially no security. Access control gives you the ability to enhance your security, and a variety of options for visitor management.

For visitors who may have long-term access such as maintenance, technicians, or contractors, you can assign an access card with the ability to turn off access at any time. At the end of their job, you can deny access to the card so they aren’t able to get in after the job is finished. Setting up an active schedule for these type of visitors is simple and easy, and provides an electronic record of each and every entry.

For short-term visitors, a key card system can utilize extra pre-programmed “guest” cards with basic access to predetermined rooms they may need access. Sign the cards in and out, and if one goes missing, simply turn off access to the card and it will no longer be of any use to the cardholder.

We manage your systems so you don’t have to

Our dedicated access control team manages over 1,000 buildings for our customers. This includes administration of more than 3,000 unique user changes a month! The EPS Managed Access administrators are able to manage cards, records, and many other programming needs. They can add new employees, and remove former ones, set specific activation dates or deactivate access cards, and even limit access to areas on specific dates or times. If you are interested in getting access control but don’t have the time and resources to manage a new system, we are able to do it for you! This is a service EPS has been offering for decades. We have experience with some of the most unique card access applications and have developed time-tested strategies to deliver seamless key card administration.

A unique system specifically for you

Every organization is different; with different needs requiring different levels of security. An access control solution from EPS Security can be tailored to fit a range of technologies to meet your specific requirements. We offer card reader systems, intercom systems, and the administration experience to help create the right system for you. An EPS Security Consultant is ready to help you find the specific access control system that you need for your facility. For more information about access control and why to choose an EPS access control solution click the link below!

Learn more about EPS Card Access

Get a Free Quote

Get Started by filling out the form or call us at 800.966.9199.
If you are an existing customer, you can contact us here.