I recently stayed at a hotel and received two room key cards to access the room: one for me and one for my brother. They are like credit cards with a magnetic strip to swipe into the door lock. My brother did the check out and turned in his room key card, but I forgot to turn mine in and didn't realize it until I was already at the airport.

What do I do about this? I'm not sure if it still works or not, or if it has any value to the hotel. Do I mail the room key card back to the hotel? Or do I just recycle the card?

  • 15
    The card is coded for your checkin only. It won't work for the same room when the next guest checks in. Commented Jul 26, 2016 at 2:10
  • 18
    Just throw it away unless they charged you a large deposit (and if so, call and explain what happened, and they'll likely waive the charge). When I worked for a hotel, we bought the card-keys by the thousands...even with full color printing, we paid less than 25 cents a card. RFID cards are a bit more expensive, but still usually under 50 cents in bulk. About 75% of guests returned the cards. Sometimes they'd return a card from a different hotel (which we just trashed). And a few times they "returned" their credit card in the drop box (they're usually embarrassed when we called to tell them)
    – Johnny
    Commented Jul 26, 2016 at 5:19
  • 4
    Nothing. Those things are made from a much cheaper (and flimsier) stock than credit cards, and are essentially disposable. Commented Jul 26, 2016 at 5:21
  • 25
    @Nayuki In my college we have similar magnetic cards. In the T&C they state you have to pay a fine of about 40€ if you lose/break one. We found out that the exact cards they are using costs 0.40€ each without buying them in bulk of hundreds. We also found out that their security is completely broken so is more cost effective to buy a machine that clones them and use the clone if you lose it than paying the fine and get a new official one...
    – Bakuriu
    Commented Jul 26, 2016 at 9:34
  • 10
    @Nayuki: just speculating, another reason may be to indirectly charge you for failing to check out, which is something they want you to do. So they hold your $10 and use it to reward you for checking out, with the card as a polite pretext. It could also be they think that should you actually lose the card, $10 is a reasonable fine for you leaving a key to their hostel lying around somewhere in the city, and presumably not notifying them (so they can cancel it) until you get back that evening. There's a lot going on besides the price of a plastic card... Commented Jul 26, 2016 at 9:55

5 Answers 5


Recycle the card however you wish. Those things are ephemeral and can't be used anyway after you check out and the hotel probably buys them in bulk.

And by "can't be used", I mean that your checkout date is encoded onto the card key and the room locks will reject any attempt to open the door past an expired checkout date in the same manner that you can't open someone else's door while you are at the hotel (or your own effin door half the time while you are still checked in).

That does not mean these keys can't be re-programmed with new room or checkout information. If you pay attention you will see the desk clerk shove the room key into a small box with a numeric key pad and hit a few keys et voilà you have a freshly programmed key ready to use (again). However if the key is physically damaged and won't take the reprogramming then the next stop is for it the rubbish bin. Here is a random link that claims to explain how these keys work Hotel Card Key Systems Explained

This of course raises the question of how easy it is to program a key in order to enter a room that is not yours. The funny thing is that while obvious, this question is actually moot as it is trivial to attack the lock itself with a simple electronic tool that exploits a fundamental design flaw in the how the locks themselves are programmed. Such a tool allows you to open all such locks with ease. I'll leave tracking down that exploit to the interested reader

Hotels are aware of this flaw, but it is going to be a long time before they roll out new door locks for every door that uses this style of pass key. Especially as a lot of hotels can't even seem to keep up with regular maintenance of normal in-room equipment.

  • 4
    Footnote font is too small. It would be better to just use an hrule (--- in markdown) to separate the optional-reading with more details section. Commented Jul 26, 2016 at 14:18
  • 3
    @MSalters Standard magstripe hotel keys are not write-once. They can be reprogrammed, such as if you extend your stay (the checkout date on the card needs to be set longer) or the clerk accidentally programs your card for the wrong room, or accidentally programs your card so the elevator won't recognize it, or accidentally checks you into somebody else's occupied room, or accidentally gives you a key that expires too soon. (All things that have happened to me at various times. I swear I'm very nice to hotel staff and don't think I do anything that would make them do this to me on purpose.) Commented Jul 26, 2016 at 16:48
  • 2
    ...... "role out"? Commented Jul 26, 2016 at 17:14
  • 4
    @PeterM: Doesn't change the fact that you're using inappropriate markup and deliberately making 90% of your post hard to read by default... Commented Jul 26, 2016 at 17:14
  • 2
    @PeterM: We're talking about the post how it is now; don't really care how it used to be :) Commented Jul 26, 2016 at 21:01

Other businesses use such cards for employee access and I have known some impose quite hefty charges to replace lost cards (say $20). However this may be more to discourage the security breaches and administration involved than to cover the cost of the card alone, which for bank cards is under a couple of dollars (and bank cards are likely more expensive than hotel cards).

Hotels cards are normally only valid for the duration of a stay (in Jakarata I had one that expired every few days!) so there is little security risk as at check-out a card valid up until then should be invalidated anyway, until 'recharged'.

You are supposed to return them and even $5 is probably a lot more than the cost of postage etc (in country) so I have posted a card back before now. However I admit I did not bother when one turned up after I had left the country.

... though some make a point of collecting them!

  • 2
    I believe the employee cards are very thick compared to hotel cards. I can try making a compare photo , I have a card from a defunct company and I sure have a few hotel keys I forgot to return over the years.
    – user4188
    Commented Jul 26, 2016 at 6:55
  • 4
    @chx: not $20 thick. I'm sure pnuts is right, some employers will think that the charge should be enough to reflect that losing a card is serious. Unless there's some really fancy printing on the employee cards, the reason it's serious isn't the cost of replacing the card, it's the cost of having employees think that because they're charged some trivial 50c replacement fee, that losing their card is trivial. The general micro-economic principle is that "a fine is a fee". The alternative is to charge nothing for replacement and try to find staff who take key security seriously anyway ;-) Commented Jul 26, 2016 at 9:46
  • 3
    I don't think the comparison with employee access cards is really valid. In particular, employee cards very often serve as ID cards and are individually printed with the employee's name and photograph. Commented Jul 26, 2016 at 12:38
  • @chx my current work badge has an RFID part that;s no thicker than a credit card (or hotel room card). The badge as a whole is slightly thicker because instead of printing directly on the badge they print the photo (along with some other information subject to change during the course of employment) in a separate self-adhesive layer that can be peeled off. Commented Jul 26, 2016 at 17:34
  • My original badge was about 4 or 5x as thick as a standard card, then it broke and was replaced with one ~2x as thick. The latter was eventually replaced with a standard thickness card. Since our badges are punched to hang on lanyards I think the thinner styles are a false economy. The thinner ones crack at the slot for the badge holder loop much faster. Commented Jul 26, 2016 at 17:35

Hotel keys are coded for the length of your stay, they will usually expire around check-out time on the last day of your stay.

Some hotels will ask you to return them because even keys which no longer open a particular room may still be used to access other key-card secure areas like the pool, business center, or gym.

Basically though, the hotel buys keys in crates of several thousand, and expects that most guests will not bother to return it. Since many hotel keys include the name and location of the hotel, I always think of them as a 'free' souvenir.

  • 6
    To add to the 'souvenir', I've seen tons of hotel keycards that essentially work as a coupon for a discount at nearby restaurants and whatnot. Commented Jul 27, 2016 at 5:13
  • 1
    "most" is an exaggeration. I'm sure they get more than 50% of the cards back, quite possibly as many as 90% - but almost certainly not 99%. Commented Feb 28, 2018 at 15:16
  • @MartinBonner fair point, "most" may have come from my experience as a customer, not a an employee. When I stay in a hotel, I reliably take the key with me :)
    – Will
    Commented Mar 2, 2018 at 22:49

I'm quite forgetful, and at one point in my life was traveling about 20 weeks out of the year on business. I regularly forgot to turn in hotel keycards. I called a couple of times and was told not to worry about it, so I stopped bothering. You'll notice a couple of things. First, they don't ask you to return the cards at checkout. (At least, traveling in the USA and Canada as I did, I was never asked at checkout to turn in a keycard.) Second, they are typically emblazoned with the hotel logo and the name of the hotel.

Now, the older punchcard keys (the ones with holes in them) and of course, regular keys are a different story, but with the newer keycards, I'm going to say that most hotels simply find unreturned cards to be a source of cheap advertising.

  • Interesting. I recently stayed at a hotel in Austria, and had to pay 5€ (or some similar sum), when I lost my key card, and they had to give me a replacement. Commented Feb 28, 2018 at 15:17
  • 1
    That is interesting. It costs them a piece of plastic and the time that's required to swipe it through the machine. I wonder how they justify that?
    – BobRodes
    Commented Mar 4, 2018 at 2:44

Nothing, you can keep it as a memento.

Last year I travelled to Singapore with my friends, our return flights were different and I was the one who checked out last from the hotel. When the receptionist asked me about the other 2 cards, I told her that we lost them somewhere. She said no problem and wished me a happy journey.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .