Meet Coin (YC W13), a startup creating a universal credit card

Interesting. Well I hope the founders worked that part out.

It looks like those cards will create a huge security issue if they are accepted.

credit cards only make up 10% of what's actually in my wallet. Now if they could minimize health insurance cards, loyalty cards, etc.. etc... then we're talking.

With that said. I still signed up :-)

I'm not wrong.

It is a violation to make ID a condition of accepting Visa at all. It is not a violation to ask for ID from specific customers, regardless of whether the card is signed or not. It says this very clearly in the "Card Acceptance Guidelines for Visa Merchants" booklet. The closest they get to forbidding it is a recommendation that you don't make it part of your standard procedure as, and I quote, "it can slow down a sale and annoy the customer".

In the case of a suspicious transaction, the merchant is also supposed to call Visa for a "Code 10 Authorization". One of the things Visa may do is instruct you to check the customer's ID.

If a store asks you for your ID, calling up Visa to report a violation won't do you any good as they haven't violated anything. As far as your jurisdiction punt, we're talking about a product intended (and only really usable) for the US.

That's a neat solution to the security problem also.

You go to the app on your phone and select the card you want. The coin will now function as that card for the next 5 minutes only. Otherwise, the coin is nothing.

Now even if your wallet is stolen, without your phone (+ unlock code, etc.) they don't have any of your cards!

Programmable mag stripe cards are really nothing new. This implementation is quite nice and sexy though. I can see immediate problems with it though:

1) Card thickness. Most makers of programmable mag stripe cards try to make their card the same thickness as a normal sized credit card. Why? Because thicker cards might scrape or get stuck in credit card readers (as old Amex black cardholders know). Unfortunately it has to be think because of the following:

2) Older iterations of this idea usually involved the bank/card issuer supplying cards with multiple card numbers preloaded on it. This card in novel in the sense that it has some writable memory that you can personally store your existing cards to. However this involves a few elements that add to the thickness of the card: It involves a non-volatile memory module for storing the cards, it involves a volatile memory module for holding information about new cards, it involves a bluetooth module for communicating between the volatile memory and your smartphone and it involves a battery to run it all.

3) The battery is non-rechargeable (because any existing type of charging point would add too much to the thickness), so the card only lasts for a specific length of time before needing to be replace.

4) There is a move away from mag stripe everywhere in the world but the US as mag stripe is really shit compared to chip and PIN for security. Even in the US, mag stripe will be phased out within the next 10 years. This card can't even store CVC security codes (the 3 digits on the back of your normal card).

5) They have added a security feature that ties the card to your smartphone such that it becomes "deactivated" (locks the non-volatile memory) once it is loses contact with your smartphone for too long. What this means in essence is that you cant use your card without your smartphone. So that begs the question: Why would the consumer adopt this instead of adopting a smartphone based NFC wallet if its available to them? Google Wallet stores any credit card I put on it, and if the merchant doesn't support NFC Google Wallet still displays an image of the card for manual number input. You might say that a merchant might get scared away from a transaction if you ask them to do that, but a merchant might get scared away by asking them to run a unfamiliar looking unmarked black card.

Regardless of the above, it is cool stuff and there is a niche that it will be useful for, at least until chip and PIN / NFC wallets become widespread in the US. I'm working on some similar ideas so I thought I'd toss in my two cents.