What Is Anti Passback in Access Control and How Does It Work?

There are many measures you can take to keep your business secure, and for many business owners, access control is a very important piece of building security. Anti passback, sometimes abbreviated as APB is a security measure that can be added to an access control system. Its main goal is to prevent unauthorized people from entering a secure area. 

What exactly is anti passback, how does it work, and what are the pros and cons? Learn more here. 

How Do Access Cards Work?

What Is Anti Passback?  

Anti passback keeps track of where people are entering and exiting your property. It controls entry by requiring access cards to be swiped out to exit an area before they can be swiped to enter that area again. Once you’re in an area, your card will not be able to access that area again because it’s assumed that you’re already there. 

Quite literally, anti passback prevents people from passing back their access card to the person behind them when they’re trying to enter a secure area. It prevents unauthorized access by temporarily disabling someone’s access card after they have already gained access. If the person behind them tries to enter using the same credentials, they will be denied access. 

To install an anti passback system on your property, you’ll need an access control system, a card reader at entrances and exits, and access cards. 

smart card

How Does Anti Passback Work? 

Anti passback works by storing information about who has entered a secure area. When somebody enters a building or other area that has a card reader, their card is then temporarily disabled. If somebody tries to use their card to gain entry, it will be denied. An administrator also gets alerted any time there is an anti passback violation and a card is used to inappropriately gain access. 

Once they swipe their card to exit the area, they will be able to enter again. The card must be used in a specific sequence, which is “in, out, in, out, etc.” If somebody tries to go “in, in,” the card will be denied. 

Anti passback can work slightly differently depending on how the system is set up. Here are a few different types of anti passback systems: 

  • Hard anti passback is the traditional system that does not allow access until the same card swipes out of the restricted area. 
  • Soft anti passback actually does allow the card to be used again, but it alerts whoever is monitoring that the card was used incorrectly. This type of anti passback is a bit less secure. 
  • Area anti passback controls card function within the building as a whole. In order to enter different parts within a building, you need to first swipe into the entrance of the building. 
  • Timed anti passback restricts access when somebody tries to use the same card for entry within a specified time period, for example, 10 minutes. 
  • Nested anti passback requires people to swipe into card readers in a specific order to gain entry into an area. This allows for a higher level of security.  

Anti passback systems are very popular and are often used in main entrances to employee buildings, parking garages, fitness centers, hospitals, resorts, office buildings, and labs. Anti passback access control can be considered anywhere you want to have control over who goes in and out of an area. 

Advantages of an Anti Passback System

An anti passback system adds a layer of security to your buildings and helps prevent unauthorized people from entering. It’s great for buildings and properties where security is a top priority. 

Antipassback is also helpful to keep a running count of how many people are in an area since you need to swipe back out when you leave. This is helpful if you need to investigate an incident; you will have a list of everybody who was in the building at the time of the incident. It’s also helpful if building occupancy or crowd control is an issue. 

Another great advantage is that anti passback and the overall access control system can be linked to the computer system. You can require employees to swipe into the building before they can log into a computer. You can also disable remote access to accounts while they are swiped into the building, which prevents someone else from logging into their account. This is a relatively simple way to add security if your company deals with sensitive information. 

Card Access Control System

Disadvantages of an Anti Passback System 

Anti passback isn’t for everyone; there can be disadvantages to the system as well. In the beginning, employees may struggle to get used to the new system, particularly if they are accustomed to walking into the building in groups. They will also need to remember to swipe out at the exit or their card won’t work the next time they try to enter the building. 

It’s also important to note that an anti pass back system doesn’t stop tailgating or piggybacking, which is where people follow in behind others. To stop people from simply entering behind someone else without trying to swipe a card, you’ll need physical barriers like turnstiles for foot traffic and gates at the entrance to parking garages. 

Additionally, if someone swipes their card but then doesn’t make it into the building, this can be an issue. They would need to contact somebody to override the system or to manually let them in. In a timed system, it could also be an issue if, for example, someone forgets something in their car and needs to run out and back in again within that timed window where their access is temporarily disabled.

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