Magnetic Key Cards

Magnetic Key Cards


A magnetic key card is a card with a magnetic strip or stripe that is inserted into a locking device to unlock a certain door or group of doors. Magnetic key cards often look like credit cards in size and shape, along with the magnetic strip at the back. They are mostly used in situations where different levels of security are needed or where locks or access may need to be changed frequently.

Most people are familiar with magnetic key cards from hotels. The magnetic key card has nearly replaced all standard locks and keys at hotels in the United States and many other parts of the world. Still, this is not the only application in which they are used.

The magnetic key card is also used to provide different levels of security. There are places where one person has access to a part of a building or company but not in another part, there are several ways that this could be handled. In the past, people with numerous places or access would likely need to carry several keys -- one for each place or door in a building. A magnetic key card could be encoded for access at different levels, eliminating the need for multiple keys.

So how do magnetic key cards work?

For example in hotels, all the hotel room locks are wired back to a central computer or server in the hotel. When the hotel reception issues you a magnetic key card, they run it through a magnetic key card writer which inputs data into the magnetic stripe at the back of the magnetic key card. When you insert the magnetic key card into the lock, a sensor reads the contained information on the magnetic strip and this are compared to information either stored locally in the lock or those in the main computer. If the data matches, the magnetic key card bearer is allowed access. Some systems operate using hardwired connections to central computers while others use various frequencies of radio waves to communicate with the central computer. Some systems also have the feature of a mechanical (traditional key) bypass in case of loss of power.

Every lock has a specific ID that can only be changed with a special device that is connected to the lock directly or through the main computer. The magnetic key cards are only programmed such that there is a date until they are valid, so if someone steals a magnetic key card and tries to use it after the time of booking, the lock denies access even if the magnetic key card has worked before simply because the date passed until it's been declared as being valid. Usually, the magnetic key card will deactivate on the checkout day at or near the checkout time. Those wanting to extend their stay will likely need a new magnetic key card with new information. Magnetic key card programming is a relatively quick and simple process, so inconvenience is minimized.

Some groups have raised concerns that magnetic key cards used in the hotel industry may contain personal information, such as names and credit card numbers. However, this is not true, according to identity theft experts. They have said that the only information usually put on a magnetic key card is the name, room number and perhaps a partial address of the guest. All other information, such as the guests' financial information, is not placed on the magnetic key card. Many other businesses and industries use magnetic key cards to limit access to company buildings or to certain areas within company buildings. Magnetic key cards provide several benefits over traditional keys including:

  • Cost effectiveness: Magnetic key card systems eliminate the need for re-keying locks when a guest or an employee has taken off with or lost a key.
  • Security: In the hotel industry, magnetic key cards are not marked with room numbers. Traditional hotel keys usually come with a room number engraved on the key or at least attached to a tag on the key. Anyone who gained possession of the key would know the room number as well.
  • Limiting Access: Magnetic key cards can be used by companies that want to prevent non-employees from entering the premises or that want to restrict admittance to specific areas.
  • Marketing opportunities: Businesses can print information on the magnetic key cards to promote their brand or advertise services and products.