Several hotels I've stayed in lately (in the Middle East if that matters) have a card slot just inside the door of the room, and it appears that the lights/AC in the room only work if you have one of your room cards placed in the slot, and will turn off about 15 minutes after you take it out. The hotel staff has referred to it as the "security card" but assumed I knew what that meant. What is the purpose of this slot? Is it just an energy-saving feature to make sure the electric shuts off when no one is in the room?

Stranger still is that the housekeeping staff insists I take the card with me when I leave (though I've got the standard 2 cards for my room so I have another one anyways). Also in one of the hotels the room lights (not the bathroom) would only work for about 15 minutes after inserting the card, so I'd have to continually re-seat it to see anything. Thank god I was only there for one night.

What is this key card slot and what is its purpose?

Conclusion: For the record, in the hotel I mentioned first it seems to only have controlled the lights. The new hotel that I'm in, it controls lights and plugs (unfortunately) and they specifically only gave me one keycard, though they had no problem giving me a second card to keep the plugs running while I'm gone. I always turn out the lights anyways, so it's not wasting power that I don't want to use to begin with.

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    Once housekeeping are finished just wedge an old frequent flier card in the slot.
    – Calchas
    Sep 5, 2015 at 15:40
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    It is an energy saving feature, as you suspected. If you don't want to deal with it, and want to avoid being chided by housekeeping, hang the "Do Not Disturb" sign outside the door, and leave one card in the slot at all times.
    – Wad Cheber
    Sep 5, 2015 at 22:26
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    Most device accept any card, no matter student card, membership card, folded white paper or the hotel key.
    – Him
    Sep 6, 2015 at 0:18
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    I stayed at a London hotel recently where reception gave me two keycards when I checked in. When I asked what for (I was only paying for single occupancy) she explained that the second one would be handy for keeping the power on when I left the room if I had chargers plugged in. I'm having some trouble understanding what the point of the whole arrangement is then. Sep 6, 2015 at 19:29
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    @HenningMakholm It's just a matter of the desk staff knowing more about real usability than the designers. Or to put it another way it's a workaround by those who would have to deal with the customer complaints when their laptop didn't charge over dinner and they blamed the hotel. Sep 7, 2015 at 10:55

5 Answers 5


This feature is becoming increasingly common in many establishments. In my opinion the purpose of such card-activated time switches is to reduce costs: the removal of the card ensures that some/all electronic appliances are turned off when the guest leaves the room, thus saving money to the hotel. Indeed guests are often given one card to access the room which is also to be used in the slot you mention to turn on the lights and air conditioning. That same card they'll have to take with them upon leaving the room, or else they won't be able to get back in. Some card-switch makers claim a 40% reduction in electricity costs for hotels using their products.

It is worthy to note that some appliances are plugged in sockets that aren't controlled by the card switch. This is often the case for the minibar/fridge, and sometimes for the air conditioning system too.

The case you mention of the lights turning off every 15 minutes is something I've never experienced, and sounds very much like if the switch was broken. Personally I would have contacted hotel management and asked for another room.

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    The case you mention of the lights turning of every 15 minutes is something I've never experienced, and sounds very much like if the switch was broken. => same here, I've been in several rooms with such a system and never had this issue. Sep 5, 2015 at 14:18
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    @MatthieuM.: "The case you mention of the lights turning of every 15 minutes" - the OP does not say the lights are turning off "every 15 minutes", but that the lights turn off 15 minutes after you have removed the key (and thus presumeably left the room). It's not a broken switch, it's a feature that allows you to leave the room in dignity (or at least in light) after putting the key into your bag. Sep 5, 2015 at 19:37
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    @O.R.Mapper "Also in one of the hotels the room lights (not the bathroom) would only work for about 15 minutes after inserting the card"
    – Lilienthal
    Sep 5, 2015 at 20:00
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    Notice that you can shove about anything in that slow at it will work. I tried paper, other cards, a knife, a key (if it reaches the button) and many other stuff. Paper is the one that works the best. Sep 6, 2015 at 15:12
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    I stayed in a hotel in Spain this past summer that had the key card slot next to the door linked not only to the room lights, but also an indicator light on the ceiling immediately outside the door. I believe this was so housekeeping could tell which rooms were likely occupied without having to knock on the door. Sep 7, 2015 at 4:03

I have seen these cards control

  • everything including plugs (so annoying to leave your laptop charging while you go out for the day, and come back to find the plug was not on while you were gone)
  • just lights but not plugs
  • lights and air conditioner but not plugs
  • just the air conditioner

Whether it exists and what it controls seems to vary around the world. In Europe it's most likely to be lights, or lights and plugs. In the South Pacific it was usually just the airconditioner (and there was a sensor on the door to the balcony or deck that would also turn off the ac) or the ac and lights. In Europe the staff generally didn't tell me what it was, in the South Pacific they generally did. I have seen these occasionally in North America.

It is easy to fool using either your second key, a card from your wallet you don't need right now (grocery loyalty card say) or a folded up bit of card like a magazine subscription card. Some hotels don't care if you do this, but in my experience, in hot places where it's hooked to the ac they care. One place said there was a $50 fine if they found the ac on when you weren't in the room. It is all about the cost of cooling and lighting a room you're not in.

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    Indeed, the charging thing is terrible! I usually go about taking photos while the battery I used the day before charges... but then found out the hard way that they simply didn't charge at all. It took me a while to figure out it was because of that unusual card slot.
    – Itai
    Sep 5, 2015 at 17:19
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    @Itai there's often one or more sockets that are powered up all the time, normally with a "24" label above them.
    – gsnedders
    Sep 5, 2015 at 20:28
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    The argument about it being a hot place makes sense in the context. In the US I've never seen one of these devices. Now that I'm traveling in the Middle East they seem to be standard-issue. Controlling AC costs there is probably a big deal.
    – thanby
    Sep 6, 2015 at 7:50
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    Once I stayed in a hotel where the bathroom socket was only active when the light was on. I didn't realise this until my electric toothbrush gave up working. These days I travel with enough cables to recharge all my devices while I sleep.
    – RedSonja
    Sep 6, 2015 at 10:08

While the other answers have elaborated on the primary reasons, I am going to point out what I perceive as a secondary reason and/or benefit:

The key has its fixed place.

To me as a hotel guest, this seems incredibly beneficial because it means the key does not lie around somewhere where I might forget it when leaving the room. Instead, it's in its fixed place in the power slot, where I will invariably look before closing the room door. If the key is still there, I will notice it (and thereby spare myself of an embarrassing request at the reception desk to help a guest who was stupid enough to look himself out), and if it is not there, I know I have taken it.

Note that by disabling the lights when the key is not in the slot, the chance that I have put the key somewhere else upon arriving at the room the last time is close to zero.

Of course, this doesn't work quite as nicely in a situation you describe:

though I've got the standard 2 cards for my room so I have another one anyways

Personally, I have stayed in hotels in various countries and never got two keys, unless I was there with my spouse, in which case each of use got one key and the method described above works again.

EDIT: This method works for any design of the "power card", be it a credit card-sized key card, or rather the keyring pendant for a physical key, like this, or this, which may not easily fit into a wallet.

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    I have a fixed place for hotel key-cards: in my wallet, tucked in sideways so I can extract it by touch. I don't need another, and don't need them braking the habit I've built to keep from locking myself out. But I grant that they have a legitimate interest in saving power, and motion-detector/IR body-heat solutions are notoriously bad.
    – keshlam
    Sep 6, 2015 at 4:33

The 15 minutes problem is most likely caused by a faulty motion detector. Many hotels use a motion detector to switch off the main lights when the guest is sleeping. You can sometime notice this after waking up, sometimes the motion detector has not been triggered and then the lights don't immediately work.

  • Would you care to elaborate? Do you mean there is no relationship between the card and the lights, even if putting the card in the slot is what enables the lights? Sep 5, 2015 at 19:36
  • @O.R.Mapper The lights are activated when you put the card in the slot, but after that a timer will switch the lights off. The timer gets reset every time the motion detector detects movement in the room. Sep 5, 2015 at 20:20
  • Oh, I see. I haven't yet encountered a room like that (the lights would be immediately or with a delay switched off upon removing the card from the slot and thereby releasing a switch), but it's true that motion detector solution is a possibility. Sep 5, 2015 at 20:32
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    I was wondering something similar, if there was a motion detector that was blocked or malfunctioning. If I'm at that hotel again I'll have to inspect the room a bit more closely.
    – thanby
    Sep 6, 2015 at 7:46

Most often a circuit breaker to cut or provide power to the room and/or to unlock the door. That's generally fairly obvious, so if not, It's possibly deprecated and bypassed. When being used as such it is typically just a power saving device. Imagine the annual cost saved, especially by large hotel chains.

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