What Is a Key Card Lock, and How Do You Bypass a Key Card Lock?

Commonly used as access control for hotel rooms, college campuses, fitness centers, and various businesses, key cards are convenient, but they aren’t without their security flaws. Key cards use magnetic stripes or radio frequency identification (RFID) to allow authorized users to gain entry to a room or building.

If you need to bypass a key card lock on your own property, there are a few methods you can try, and it’s a good idea to know what tactics criminals might use to try to gain entry to your building. Here, we explain four ways to bypass a key card lock. 

key card lock

What Is a Key Card Lock and How Does It Work? 

A key card lock is a type of lock used in access control. It requires users to either swipe an authorized magnetic stripe card or bring an authorized radio frequency identification (RFID) card in close proximity to a key card reader. When the card is swiped, the door unlocks.

There are many reasons businesses opt to use key card readers. To start, these types of locks are easy to install, and they don’t require any wiring. This makes them accessible for a variety of locations. Additionally, it’s easy to assign new cards and then deactivate them later when they’re no longer needed. This is ideal for hotels and other businesses that have a quick turnover. It reduces security concerns because business owners don’t have to worry about lost keys, and they can quickly assign cards to new guests. 

While ideal for many types of businesses, it’s important to understand the security risks involved with key card locks

Types of Keycards

Why Bypass a Key Card Lock 

There are a few reasons someone might want to bypass a key card lock. The most benign reason is that somebody lost their card and needs to enter their hotel room or other secure area. Similarly, a building administrator might need to gain entry to an area where a lock is malfunctioning or where a master key isn’t working. 

Criminals try to bypass key card locks for more nefarious reasons. They may wish to gain access to information inside a room, steal property, or harm individuals inside. Of course, this is a major concern for people who use key card readers to secure their business or property. 

why bypass key card lock

How To Bypass a Key Card Lock 

There are many ways to bypass a key card lock. It’s typically easiest to bypass key card locks that are more outdated. Newer models have more safeguards in place to prevent people from breaking in. Some of the methods that worked in the past may not work well anymore. 

Arduino Microcontroller

One such outdated method was incredibly simple and could be done in less than one second. Older Onity key card locks had a DC power socket under them. The power socket was used for the battery and to program the lock when the code was changed. Unfortunately, this socket also allowed hackers to gain access. With an Arduino microcontroller plugged into the socket, people were able to open the door. 

After this problem came to light, it was largely fixed by replacing the locks, however, some companies still use the outdated locks that possess the security vulnerability. Any of these outdated locks that are still in place could be hacked the same way. Anyone who uses outdated Onity key card locks should replace and update them immediately. 


Another vulnerability in key card locks is difficult to stop: piggybacking. Piggybacking is when someone holds the door open for the person behind them or when someone sneaks in by catching the door before it shuts. The best way to prevent this is with an anti passback system. This type of system uses a variety of measures to prevent people from passing back their card or from sneaking in behind somebody else. 

Programming and Coding 

Another way to hack and bypass a key card lock isn’t as accessible to the average person. However, people with the right training in coding or programming and the right equipment may be able to program a new card. This requires a good amount of equipment, including a key card encoder, a laptop, a USB card reader, and extra key cards. Here’s how it works: first you use your USB card reader to get the information off the existing key card, then you transfer that information to your computer. From there, you can program and code that information onto your new key card. 

This method, of course, requires you to first have access to an authorized key card. You can program a new copy of a single lock key card or of a master key. While this method is more complicated, it does present a security risk if someone gets a hold of a card and has a motive to enter your building or room. 

Lock Picking 

It’s possible to pick the lock on a key card lock in a similar fashion to how someone would traditionally pick a lock. For this method, you’ll need a credit card or similar card from your wallet. It’s likely the card will get bent and damaged as you try to pick the lock, so opt for something that isn’t important, maybe an expired credit card or a store rewards card. 

First, slide the card between the door and the door frame at the location of the lock. Alternatively, you can start above or below the lock and then slide the card down toward the lock. Next, bend the card toward the doorknob. You may need to try this a few times, and you’ll likely have to wiggle and maneuver the card around a bit. When you hit it at the right angle, this can push the lock in and open the door. 

Note that the curve in the lock needs to be facing toward you for this to work. If it’s facing the other way, it won’t work. The key card lock also needs to be the only lock engaged. If there is a deadbolt engaged, you may be able to unlock the key card lock, but you still won’t be able to open the door.

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