A 40 Year Evolution of NWMLS Keys & Keyboxes

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Since its inception in 1984, NWMLS has provided our membership with the most advanced technology to safely and securely access listed properties.

Let’s take a walk through the last four decades to reminisce about the evolution of NWMLS’s real estate keys and keybox technology.

Fun Fact: The first real estate lockbox was invented in 1955 by Delbert Williams who would go on to found Supra – the company that provides keyboxes for NWMLS brokers today!

1984 – Title Keyboxes

When NWMLS (then called Puget Sound Multiple Listing Association, “PSMLA”) was first formed, our membership used Title boxes and keys to access listed properties. PSMLA was formed when four innovative multiple listing services: Eastside Brokers Association, North End Brokers Association, South West Multiple Listing Service, and Real Estate Multiple Inc., merged to create a not-for-profit corporation to provide listing services to real estate professionals in the Puget Sound region.

At this time, each of the four organizations had their own Title key and keybox system that could not be used with one another. Real estate brokers and appraisers had a unique key number on their metal “key” device, which allowed them to open any keybox for a property listed in their MLS. 

Mid 1980s – Titan Keybox

As the merger occurred, PSMLA moved to the Titan keys and keybox system.

This system was more advanced, with each real estate broker or appraiser using a more advanced “key” like device with a unique key number to open keyboxes.

Late 1980s – MARC Keybox

The MARC keybox system used an imprinting method to record the keys that opened it. Each broker or appraiser had a metal key with a unique “showing code” for their specific key number. Brokers and appraisers would insert their key into the keybox, turn it, and then enter their PIN code to access the key. When the key was turned, the showing code that related to their specific key number was stamped onto a strip of foil inside the keybox.

If a listing broker needed to obtain a list of brokers that showed their listing, for example if a showing broker ever forgot to leave their business card at the property, or didn’t return the key to the keybox, the listing broker could bring the keybox to PSMLA. PSMLA staff would remove the foil strip to view the list of unique showing codes, and match the codes to the corresponding broker’s key number.

Early 1990sSupra Advantage Express with Supercard

The Supra Advantage Express was the first electronic key and keybox system provided by PSMLA (Due to PSMLA’s expanding services, the membership voted to change its name to Northwest Multiple Listing Service in 1996). 

Real estate brokers and appraisers would insert their Supercard device into the keybox, and then enter their PIN code to access the house key. The keybox would electronically record the NWMLS brokers and appraisers that opened the keybox. The Supercard electronic key device needed to be docked and charged each night.

Early 2000sSupra iBox & DisplayKEY

With the introduction of the Supra iBox, NWMLS brokers and appraisers could use their Supra DisplayKEY to beam an infrared signal to open the keybox and retrieve the property key. The iBox recorded the date, time, and DisplayKEY PIN number unique to each holder every time the keybox was opened.

The DisplayKEY expired at midnight, requiring a nightly eSync. It came with a modem-equipped recharging cradle for recharging the battery, and connected to an ANALOG phone line that would dial out to auto-update record showing information and broker communication.

Mid 2000s – Supra eKey Palm Pilot

In partnership with Palm, Inc., Supra launched their first “eKEY” product using a variation of the Palm Vx PDA (personal digital assistant). Real estate brokers and appraisers used a Supra “clam shell” add-on that clamped over the eKEY Palm Pilot, and allowed them to enter their PIN code and open the keybox. In addition, brokers and appraisers could use the Palm Pilot to view listing details, view the property on a map, and find contact information for other NWMLS brokers and appraisers using a roster feature.


The new ActiveKEY device replaced DisplayKEYs. No cradle was needed! Wireless updates delivered showing data immediately, continuously, and automatically to listing brokers. ActiveKEY worked seamlessly, connecting to ALL cellular towers to provide the best coverage; offering updates and keybox access even in areas without cell coverage.

2010seKEY App & Fobs

The first Supra eKEY mobile application allowed NWMLS brokers and appraisers to use their mobile phones to open keyboxes. Brokers would sync the eKEY app with an eKEY fob, which used Bluetooth to open the iBoxes. Brokers would simply point the fob at the infrared point on the iBox and press the power button to obtain the key. 

2014Supra iBox BT LE

NWMLS held a one-for-one exchange to replace all assigned Supra keyboxes with new, Bluetooth enabled Supra keyboxes, the iBox BT LE. At this time, brokers could continue to use an ActiveKEY or upgrade to the eKEY service. Not all devices were compatible with the eKEY service and older iPhones still required an eKEY fob to open keyboxes.

2016Supra eKEY Became Compatible with Most Popular Phones

The Supra eKEY app became compatible with even more mobile phones, including most Android, iPhone, iPad and some Blackberry devices. eKEY updated wirelessly, allowing NWMLS brokers and appraisers to do business anywhere with ease. No additional hardware was required for most phones, although eKEY fobs were still required for older phone models.

2020ActiveKEYs Retired

All cellular carriers shut down the 2G technology that was used by Supra ActiveKEYs, and NWMLS brokers and appraisers were transitioned over to the eKEY smartphone app.

2024 and Beyond

Over the last four decades, NWMLS has brought together the smartest tools in real estate to help our members provide best-in-class service during the home buying and selling process. We are continually reviewing technology products to ensure our membership has access to an array of products, services, and support to help them deliver an exceptional experience to their clients.

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