Criminal Mind

I've noticed that a number of brick-and-mortar stores have begun asking me for the last four digits of my credit card when using that mechanism to pay for my purchase. When asked about this, I've been informed that some people have been replacing the magnetic stripe on the card with a different one, so that the numbers on the magstripe are different from the numbers imprinted on the card.

In most instances so far, I have been asked to verbally recite the numbers, or to type them into a keypad. I fail to see how this prevents the sort of card counterfeiting it is intended to stop. If I really wanted to execute this kind of crime, I would merely have to purchase a tank of gas with the phony card first: almost all gas stations print the last four digits of the card on the receipt!

The only meaningful way to prevent this kind of fraud is if one were asked to surrender the card, so that the clerk could verify the digits themselves.

4 Comments

On Oct 4th, 2007 at 02:23pm Bill added:

Often the display panel will have a message instructing you to hand the card to the clerk, other times I've seen the message to confirm the last four digits. Before the magnetic stips people would file down the raised numbers on the credit card so they would not imprint on the carbonized forms. People will always find a way to circumvent the "system"!

On Oct 4th, 2007 at 05:07pm Bob added:

Usually better vendors will ask you to show or to type in the 3- or 4-digit security code (the number that is not printed in raised letters). This is an additional layer of checking that matches the individual card number against a batch number (and helps to frustrate carbon-reading).

However I have not yet witnessed what you're describing. If they ask you to give them the card, it seems like a very good doublecheck, per this:

http://tinyurl.com/2r978c

Except, this document warns that these days you shouldn't even give up your card, as it can be read into a separate reader and the security code noted.

If you to input the number, it seems completely pointless except perhaps as security theatre. I also wonder what the vendors are thinking??

On Oct 5th, 2007 at 03:41pm Giga added:

I noticed this while at the big blue home improvement store, but nowhere else (yet). I also noticed at a discount department store that they now also make you type in your billing zip code when you type in your pin.

On Oct 8th, 2007 at 09:33pm Elfboy added:

That big blue home improvement store is the only place I've noticed this practice thus far. When I asked why, they said they could use the four numbers to look up your receipt should you need to make a return.