6 Reasons Why Your Hotel Key Card Stops Working

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Checking in to a hotel I typically request 2 keys even when traveling solo. I pride myself on being organized, and whether returning after a quick trip down the street or a long day’s excursion, I proudly pull out my room key card and slide it in the slot without rummaging around in a bottomless bag.

Most times I get the happy green light and in I go. Once in a while, the light blinks red and the door stays closed. I try the key again, slower, to no avail. If I have the 2nd key with me I’ll take that one out and try it. Sometimes there is success. Other times, the stubborn red light taunts me and I resign myself to the fact that I’ll have to trudge back down to reception to ask for a new key.

Why did my key card stop working? Front desk staff almost always smiles and has an easy response such as, “Did you put your key card next to your phone or camera?”

The answer has been a sheepish yes (camera), but other times I am completely mystified.

It’s usually a minor inconvenience, but sometimes it happens more than once at a property. Sometimes three, four, five or more times. Usually when I am tired or have my hands full of takeaway food that I’ve brought back to enjoy in the room.

Other people report the same thing. They keep the key in a separate jacket pocket, on top of a stack of papers or even in their hand the entire time out of the room (if doing a quick errand).

Would you be surprised to find that it isn’t always your phone that demagnetizes the room key?

Here are 6 reasons why your hotel key card stops working –

6. Can your cell phone demagnetize your key card? Yes, but it probably doesn’t. How about another credit card? Yes, but almost never does either. It’s true that any magnet has the ability to impact the mag stripe on the back of the card. Magnetic handbag clasps and phones are all suspect. However, do you notice that credit cards are hardly ever demagnetized and you keep them for much, much longer?

5. It has to do with the quality of the mag stripe on the back of the card. Mag stripes come in two different levels of coercivity (the level of how difficult it is to encode and erase info from the stripe). Hotels tend to use low coercivity (LoCo), which is also what many theme parks use. Designed for short-term use, the data can be changed and erased easily. Credit cards, bank cards, and many employee access cards utilize mag stripes that are considered high coercivity. HiCo has a much stronger magnetic field (by about 8x) which is much less likely to allow accidental erasure. If you guessed that the LoCo type hotels use is less expensive, you’re correct. Putting the hotel key card on a table where a TV is present, next to a camera or even in your wallet or purse near another mag strip card could wipe the data or damage it.

4. Another factor is physical damage. If you dropped your card on a hard surface it might have gotten nicked. Scratches, crusted cracker-crumb bits and folds might make it harder for the card to be read. Cards left in the hot sun, rubbed by beach sand in a pocket or stepped on by a dog might look just fine but may have lost the ability to open your door. Cards that are turned back in to the hotel are re-used endlessly, and once they get stuck together with gunk, staff will finally throw them away. Did you know that hotels almost NEVER clean room keys? This is also something to keep in mind for all you readers that like to keep a stash of colorful key cards as a momento from vacations. Maybe consider using a sanitizing wipe before tucking them away.

3. The age of the card and the encoding equipment will change the effectiveness of key cards. SecureIDNews says that often, “encoding equipment needed to be cleaned or maintained” when an investigation of ineffective key cards was done. This means that the hotel might be using old equipment or maybe it hasn’t been cleaned in a while. The mag stripe will eventually wear out, and after hundreds of times of running cards through the low-cost encoder it is only a matter of time before the data becomes garbled and worn out.

2. Timing. Key cards might be programmed to deactivate at noon on the date of your check-out. If you have two back-to-back reservations the front desk hostess might not have connected them so your key might stop working when your first reservation is over.

1. A secret, sneaky tactic that front desk agents have control over, according to the book Heads in Beds: A Reckless Memoir of Hotels, Hustles, and So-Called Hospitality

Quoted from the book –

“Any arriving guest should receive what are referred to as initial keys, which are programmed to reset the door lock when they are first inserted, deactivating all previous keys. Not until the keys expire or a new initial key enters the lock will the keys fail to work. With a “key bomb,” I cut one single initial key and then start over and cut a second initial key. Either one of them will work when you get to the room, and as long as you keep using the very first key you slipped in, all will be well.

But chances are you’ll pop in the second key at some point, and then the first key you used will be considered invalid. Trace that back to me? Not a chance. Trace that back to the fact that you told your 9-year-old daughter to shut her mouth while harshly ripping off her tiny backpack at check-in? Never.”

I’ll continue to keep my key card in a location separate from my camera (sometimes), and definitely throw it away at the end of my stay. Whatever the reason for card’s sudden refusal to open my door though, the next time my key card stops working I’ll try to be kind to the front desk agent that fixes it for me. Even though it is possible that some key cards are “key bombed” I figure that hardworking front desk staff have more important things to do with their time than purposefully create a situation where I’ll have to return back to them for more work on their end.

Did you like reading this post? Here are a few others you might be interested in –

Do it Yourself: 5 Ways to Cook in Your Hotel room

7 Great US Hotel Pools to Redeem Points for

Magic of Miles in Japan: Tokyo, Kyoto, Hiroshima and Osaka

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  1. Randy

    And all along I thought it was my magnetic personality.

    • Melinda

      Randy, that’s reason #7. 😉

  2. Hemant jain

    As a firm that has been in the business of manufacture and supply of custom printed keycards based on magnetic stripe and RFID technology i have a extremely good idea of what the exact reasons are. Most have been outlined very well in the article above but i can help give weightages to what contributes to the problems.
    a] Loco 300 OE cards – this is the number one reason. All the hotel needs to do is to change the encoder at the front desk to HICO -2750 OE and the problem will get 90 percent reduced. No change of locks is needed. the cost difference per key for the Hico magnetic stripe cards is extremely nominal less than 2 cents per key and it will go a long way in problem resolution.
    the second reason is inadequate cleaning of magnetic heads both the lock head and the encoder head in the front desk. this results in a poor read/write performance of the magnetic stripe and the high failure. Regular use of cleaning cards eliminates this problem by 95 percent.
    next the keys have to be cleaned with a soft cloth if recycled by the hotel. this is because build up of grease and dust transfers onto the magnetic head resulting in a drop in performance.
    All other causes mentioned do not contribute to more than 2 percent of the complaints.
    It is a complete myth that RFID cards perform better and if the above precautions are taken hotels can save a huge amount of money
    as well as eliminate guest complaints on this count.
    We have worked with several hotels that cared to ask for our help and have resolved this problem comprehensively each time.
    Our domain expertise and neutral position helps us to offer objective and impartial advice.

  3. minoti

    I completely agree with the analysis by Hemant above. Hico magentic stripe usage as is done in the banking industry is a very simple low cost method of eliminating all the problems.

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