If you run a real estate business, you'll be familiar with the concept of lock boxes. These secure devices hold house keys and attach to a doorknob. Agents can open the lock box whenever they need to show a prospective buyer around a seller's home. Most lock boxes open with an electronic key card and require a manually entered code available at the listing office.

Locate Your Key Card

You'll need an electronic key card to open the lock box, and the only way to get a key is to be a member of the Multiple Listing Service. They key looks just like a credit card but with an embedded digital chip. All keys cards have a unique identifier inside them so that when someone opens the box, the chip registers the agent who opened it and the date and time they entered the house. This is a good way for sellers to find out who showed the house and how many showings are taking place.

Renew Your Card

Most models expire the card at the end of every day, so you'll have to refresh the security data daily before you attempt to open the lock box. To do this, insert the key card into the chip card reader just as you would with a debit card when making a retail purchase. Log onto your computer and open the lock box software. Enter the lock ID and your password. The software and the key card will now "talk" to each other and upload all the card's time stamps. That way, the seller can see which agents entered the home.

Locate the Lock Box

Most sellers place the lock box in a conspicuous position such as on the door knob, but some sellers feel more secure if the lock box is hidden out of sight. Popular locations include a gas meter, the garage or on a gate. Make sure you know where the lock box is before you arrive at the seller's home.

Open the Box

Insert the key card into the slot at the front of the lock box. Enter your passcode using the keypad on the front of the box. This usually consists of a four-digit personal identification number. Agents are assigned their own unique PIN which they are not permitted to share with other agents. If you've entered the PIN correctly, the green light displays. You can now open the lock box by pressing the manual release button. The front opens, and the house key should be inside. You now have access to the home.


If you followed these steps and the lock box does not open, check the restricted hours. Lock boxes can be configured to operate during certain hours. For example, you can restrict the lock box from opening before 8 a.m. or after 9 p.m to prevent unscrupulous agents from having a party in a vacant house. Unauthorized access to a home is a violation of the National Association of Realtors' Code of Ethics. An agent may only use the lock box in accordance with seller's rules.

Infrared and Smartphone Lock Boxes

Some newer models of lock boxes use infrared technology that detects the presence of the key card from around a foot away. With these devices, you don't have to put the key card into the lock box device. Other models synchronize with a smartphone, so no key is required. To open these devices, download an app on your smartphone. Check the manufacturer's instructions for details.