What Ever Happened To One-Time Credit Card Numbers?

I seem to remember hearing about the idea of one-time credit card numbers years ago (ah, here’s an article about AmEx doing this five years ago), but haven’t heard a whole lot lately. This seems like something that merits more discussion, because in the end it should be a fairly standard feature for most, if not all, credit cards. I was talking with someone at work about this and we came up with a couple of different ideas and issues that could eventually come out of the one-time credit card number idea.

First on the list is the length of credit card numbers. If this idea is going to really take off, then the size of the number probably needs to increase. This led to the idea of assigning a “person” and credit card number prefix (perhaps the first half of the number?) and then using the rest of the number for the one-timeness functionality. This could lead to using alphanumeric strings for credit cards instead of just numbers. I think you get the idea, if we make the space big enough there are a lot of possibilities.

These brings us to the next thought, why limit this to simply a one-time number (or string)? If I’m going on a three day trip to Disneyland it might be nice to have a single credit card number that I would only use on that trip. So I have a number (or string) generated and would be able to associate that number in Quicken or MS Money for my Disneyland trip. This could be done by requesting a number that would only be valid between a certain date and time range and optionally for a maximum number of transactions. This concept could also apply for online purchases by requesting a number that is good for only one transaction and for the next 15 minutes. If this was the only type of credit card you used it would make the traditional expiration date meaningless.

The Disneyland trip example runs into another snag though, in most cases you’d need to swipe card through a reader for transactions. So now we need a way to easily program these generated numbers in cards. If we wanted start based off of the current limitations, these programmable cards would have to the same form factor as the current cards, with a magnetic strip that is readable by todays systems. This is because not all transactions just swipe the card, think about those gas station systems that pull the whole card in. One way this could be done is to have disposable credit cards that could be easily programmed with your generated number. They would be available like phone cards, at pretty much every AM/PM or truck stop.

There are still other issues that would have to get sorted out, like would an average person be able to easily use the device to program these cards? Do the credit card companies really work fast enough for time based limits like 15 minutes to really work? Would we be able to successfully overhaul the credit card networks to make use of new technologies, such as alphanumeric strings and personal prefixes instead of numbers? Is it likely that we’ll ever be able to widely deploy new types of credit card systems in a decade or are we stuck with what we’ve got?