5 Reasons why a key card can not work

It’s a scene that happens every day in many hotels

There’s nothing worse than holding your room card and not being able to get into a hotel room.

Our old friend Nicolas Cage’s key card was rejected in the movie‘The Unbearable Weight of Massive Talent’.

In almost all key card hotel lock the red indicate light is telling-the key card not working, can not open the door.

What caused these issues?

Firstly lets learn more how the lock works

From the above figure, we can see that whether the door can be opened is related to 2 stuffs- the card and the door lock.

Inside lock- lock inside parts, including MCU, reading data.
Outside lock- the key card, indicate light.

Key card Expiry

As everyone knows, the key card stored a using period. Manage the use time of the door lock-this is the main significance of the existence of modern key card hotel locks.
So when a room card doesn’t open, the first thing to checking whether the card is expired.
And it’s not just the expiration,using the key card too early can also be rejected.

Why firstly check the card when can’t open the door? 
Because checking the card is the easiest and fastest.


Lock Faulty

If there’s nothing wrong with the card, the possibility is on the lock.
There are many reasons make lock faulty.

  • Electronic component failure.
    Every door lock has an MCU, a memory unit, and a whole bunch of other components, like diodes, resistors, capacitors.
    The electronic part of the door lock is mainly responsible for information reading, analysis and command transmission.
    However, every brand hotel key card lock has its own design plan, the plan contains the all models, types and various brands of the electronic components.
    There are countless combinations of them, and the effect is not the same. For example some are stable but some not.
    Some in high costs but some very cheap.
    If some of these components are of poor quality, which can cause the card to fail to read.If key card can not be read success, the lock is not able unlock.
  • Deadbolt microswitch malfunction.
    Deadbolt(double locking) is a privacy feature.
    When people who inside room he don’t want others open the door,he can activate the deadbolt.
    Some locks deadbolt is pure electronics and some are mechanical plus electronics.No matter which one it belongs, there surely a microswitch behind.

    this is a deadbolt microswitch malfunction on Onity hotel lock

    This is actually a very common problem. It happens very often. In the first five years of my career, I was in trouble like this a lot.Let me draw a picture of how it disables the key card.

    when the microswitch of deadbolt not working properly, the lock is always in ‘deadbolt enaged’ status, so the lock will reject guest key card always.


  • Clock chip defect.
    Normally there is a clock chip inside the lock, it gives the clock time to lock. If this chip lost time or defect, the lock will reject the correct and valid key card.

    Key Card Faulty

    There are two types of key card- The magnetic stripe key card, and contactless(rfid) key card.

    Magnetic stripe key cards became popular in the late 20th century

    Contactless key cards became popular in the beginning of 21th century
  • Magnetic card(magstripe card) in long – term friction operation, the card is easy to damaged
    When i was in NYC for one week in 2015, in a hotel i must replace my guest key every 2 days, in the front desk.Every time I stood in front of the lock, I wasn’t quite sure my card would open it.
  • RFID cards also have a lifespan. Although it has a theoretical lifespan of 100,000 cycles, it often fails to reach the ideal lifespan due to problems with the chips and manufacturing process used by manufacturers.

Operating incorrectly

The incorrect operating also cause read card failed.

Went to Wrong Room

Yes that’s not kidding, went to the wrong room(door) could make a key card not working.
Because the key card only works on the door(room) which match it stores.

There is a small story-Last year 2022 some day, i stay in a hotel with my wife and kid. In the middle night when we sleeping deeply, somebody shake our door strongly! It scared my wife and kid.

Just as I was about to get out of bed to see what was going on, the shaking suddenly stopped. I immediately got up and moved to the peephole and i saw a guy when to the opposite door and opened it.
There is a room number on that door-1428, but mine is 1423!
When the hotel manager asked me the next day if I was happy with the staying, I told her what had happened. 
Maybe it wouldn’t have happened if they hadn’t made the room numbers so similar. 

Why is it easier to get the wrong room in a hotel?

  • Similar doors
All the doors are the same and the only difference is the room number

So, you can never go to your house by mistake but you’re probably find the wrong hotel room.

  • Dark lights
    Usually the hotel has a very warm corridor layout, let people have a feeling of home – relaxed, leisurely.
    So the lighting is relatively soft and not harsh

    In such a dim environment, the only thing that can be identified is the room number, if its lighting is not good, it is easy to go to the wrong room.
  • Room number and card are separately.

    Some hotels will put the key card in an envelope. The card envelope is used to mark the room number, and the key card there is no room number.
    If lost the envelope,even hold the key card, it can not find the correct room.
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My name is Richard Alvin.Creator of Hotel Lock Pro concept. 16 years experience of electronic hotel door locks. Free illustrator and be good at graphics and images. Game console fans. purpose of this site is to share and exchange hotel lock products with people related to the hospitality industry,such as hotel sourcing, hotel owner, hotel hardware maintenance, hotel lock installer, even hotel lock manufacturer and hotel lock resellers. I hope you can find the information you need at this site.


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