What's the point of providing your CVV (for credit cards)?

[nwwong]

So the CVV number are the 3 digits on the back of a credit card. I've heard you should never give this number out over the phone or else your credit card can be used by thiefs to make purchases.

So, how come some websites ask for your CVV and some don't? Ie. I ordered some books from chapters and they didn't require my CVV. Yet if you make a donation to the Red Cross online, they want your CVV.

[user01]

yea, I was wondering the same thing too

How come?

[hoob]

The CVV/CVV2 number on your credit card is something that's not encoded on the magnetic stripe on the back, so cannot be captured by a skimmer automatically. So it's basically an extra level of validation on your transaction, especially online when the card is not physically there.

So in essence, just like your credit card number itself, don't give out that number to businesses or entities you don't trust. I've worked with payment systems where it's mandatory for the authorization to proceed, so in general I think it's OK for vendors to ask for this number.

In store, often you'll have the cashier re-enter the last 4 digits of the card number as well, to verify that what was on the magentic stripe matches the front of the card. These are all just small extra steps to reduce payment fraud.

Oh, and not related to the Red Cross in general but often, charitable organizations are are by fraudsters to test if a stolen card number is still "good". This is why places like the Red Cross might be more strict. How? If the number has been reported stolen/compromised, the transaction will be declined, period. Otherwise, it will essentially ALWAYS go through, hence confirming the stolen card as "still good" -- since the "anti-fraud pattern algorithms" in place will rarely flag a charitable donation payments (amounts low and not expected to be part of a regular purchase pattern.)