Implanting a London Oyster card transponder in a ring

Dhani Sutanto removed the transponder from a Transport for London Oyster card (a RFID-based stored value card used to pay for rides on public transit) and implanted it in a ring, making a lovely bit of snitchy jewelry that gets him on the bus.

Oyster Ring (Thanks, Phoebe!)


  1. Bearing in mind that the maker says it’s illegal to do so and use the ring, which in practice is a modified oyster card, I really wonder what makes it illegal…

    Is the oyster card property of Transport for London?
         (I don’t think so, as I had to pay for the card on top of the pre-paid fare last time I went to London)
    And if not, what act in British legislation prohibit the action?There are other countries out there that actually give a customer the right to make such a modification, provided the card is property of the user, and not of the transport company itself.

    1.  It’s probably  not illegal, just against the Terms and Conditions.

      It seems to be quite common nowadays to confuse “Against the rules” with “Against the law”

    2. I would overwhelmingly suspect that the cards(if they are anything like the MiFare classic-based RFID cards used in other transit systems) have some sort of never-been-tested-in-court-but-sure-looks-fancy boilerplate printed in small letters to the effect that: “Card remains property of transit agency, may not be yadda, yadda, not responsible for balance if card is lost, stolen, mutilated, etc, etc.”

      Given that paying a fee for permanent use of one certainly smells like a ‘sale’, I wouldn’t want to be the guy who actually litigates that legalese(and, in any case, the unit value of an RFID card of that nature is about the same as a lukewarm cup of coffee, so we aren’t talking major damages here); but they certainly do their best to suggest that any interaction with the card not intended by the issuer will cause your spleen to fill with barristers.

      1. It is in their conditions that “All Oyster cards remain our property and must not be intentionally damaged, altered or tampered with in any way”.
        Technically it’s not a fee, it’s a “deposit”- you can return your card to TfL and be refunded what you paid for it.

    3. It IS property of transport for London, the £3 you pay for it is a deposit. I think that’s how they’re able to dictate that kind of usage.

      This ring is naff though, tha magic wand I saw a while back was a great conversion :)

    4. it’s likely illegal because some types of higher value and/or discount oyster cards have your name and picture printed on the back, to ensure they are only used by the person the card is registered to

      personally, I would gladly cut up several 1,000 of these Oyster cards:

  2. Does the intact card work more quickly than the ring? It seems like the moment between when the ring is applied to the detector-thingy and when the thingy beeps is long enough to slow a queue during rush hour. The antenna wire may be the same length in the ring, but it’s much bigger in the card.

    1.  Oh thank you for that Lovely lol early in my morning! An excellent piece of performance art, I love the guy’s expression in the background when she finally gets through!

  3. The best similar idea I heard of was to put the chip in the end of a wand, then dress up like a wizard, walk into the underground and bop the wand on the reader with an “open sesame” spell – and it works!

    1.  What would the problem be? The inspectors just check that the “card” has been touched in properly. They rarely even ask you to take it out of your wallet. Mine is tucked away in my wallet and last time I was checked I just put my whole wallet onto the reader and they checked the display on the reader and moved on. They never asked to see the card itself.

  4. Very sure oyster card has a RF coil, doing this will render it inoperable? Those fancy ethnic bangle made from  metallic helical coil are known to induce sufficient current to cause burns. 

    1. The ring appears to retain the RFID pickup coil(albeit in what is probably Not Exactly the shape that the RF guy intended).

      I’m sure that it is making whoever did the math cry; but real-world RFID systems have some slack built into them, because people expect them to work under sub-optimal conditions. You can get away with a bit.

  5. What I would really love to do.. stuff one of these in a fake oyster and just confuse the hell out of people..

    1. That actually seems like the sort of idea that could move a lot of slightly cheesy injection-moulded keychain fobs…

      As long as they refrain from having a ‘loveable’ cartoon character named ‘Wampum the payment Oyster’, they might even get away with it.

  6. I really don’t understand why transit companies don’t create and sell “premium” cards — it could be a pretty solid revenue stream, and it’s easy to stick RF tech in just about anything; jewelry (bracelets), wallets, stickers, watches… 

    1. They have a lot of problems with fraud on the transport system in London, I guess making them uniform is easier, like with money.

      That said there’s a big market for card holders.

      1. When I went to London, at first I carried my Oyster Card separately (I don’t carry a wallet, just driver’s license and credit card in a fitted pouch my phone goes in) and took it out to use… but then I saw people putting their entire wallets against the readers and not taking the card out.

        Granted, having it on a ring is easier even than taking your whole wallet out, but I’d rather do that than have to remember to put on your (ugly) ring every day. I guarantee that if I needed something like this regularly, I would forget it frequently unless I kept it on me at all times anyway, which is why putting this in a piece of jewelry or something like that doesn’t make sense.

        But… if you’re the type of person who can remember things like that easily, then it’s a cool idea :)

  7. This inspired me to try dissolving an Orca card (Seattle public transit) in some acetone for the second time, with an eye towards implanting it into my smartphone. (The first try failed because I used nail polish remover at first; I guess this left some kind of residue that blocked the action of actual acetone when I went and got some of that.)

    1.  You’d need to be sure you got acetone nail polish remover not non-acetone.  Of course, as pointed out at the maker’s website, not all card types will dissolve like that.  Different materials or something.

      1. The nail polish remover I used had acetone in it, go fig.

        But I can verify that straight acetone works on Orca cards; the chip and antenna from one of mine is now carefully re-wound and taped inside my phone.

  8. The most triumphant example of this I’ve seen was a flamboyantly gay young lad with a toy fairy wand.  The chip was in the head, and when he tapped it on the reader it still made the built-in sparkly “schwing!”  Every turnstile a dance move. 

    1.  Gotta keep that population frightened of something.  Everybody down!  Wand, wand, wand!

  9. The sad people who work on the underground and trains tend to be a stunted jobs-worthy lot who would never accept something that had the functionality of an oyster card but doesn’t look like one. it would blow their tiny minds. 

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