How do credit card companies discover abnormal spending patterns? A guy at work had his card/number stolen while he was on vacation, and they called him about the charges in location C, not on location A or B where he was travelling to (which are distinct from where he actually lives). How do they know that?

Also, has anyone here noticed their card/info stolen without the CC company telling them?

When my check card was appropriated a few years ago, I noticed it first when I saw a few $20 entries for Second Life appear on the checking account when I was doing my daily look at the bank's website. That was Thursday, and the bank couldn't do anything about those entries until they went from "pending" to "final." Then, on Monday morning at 8:00 am, I got a call at home from the bank telling me that over $1000 in charges got put on my card on Sunday and that sent up their "fraud" flag. Since I already was on record complaining about those small Second Life charges a few days earlier, they gave me no problems about the obvious fraud and cancelled my account immediately.

Also, has anyone here noticed their card/info stolen without the CC company telling them?

I have a couple of times. Usually when the CC company calls me it's because I've gone on my first vacation in a long time.

Here is an account from a guy who used to work in a fraud center: [link]

Maybe they have an algorithm that looks at what you've done in the past and "figures out" what you're likely to do?

The day after Black Friday, I got a call because my card had been used to make some weird electronics purchase that morning. They may have been extra diligent after the big shopping day, but I'm not entirely sure how they knew it wasn't me. I think it may have been a ridonkulous amount, which would be unlike me. But I've wondered how they know some of my other potentially weird spending patterns aren't fraud.

Interesting account, Tom. I think it might have been the gas thing that triggered the alert on my co-worker's card. And it makes sense that if you travel on the card and then spend money at your destination, then they know. But I never do that. I buy big ticket things like airline tickets on one card, and meals, etc, once I get there on a different one. But I haven't had my info stolen in 15 odd years. And then they were very stupid, because they used it for mail order.

I had a suspicious spending alert call from my bank a few months ago. It was right after I found out that I'd be getting a little money back from my tax returns, rather than having to pay out. And my purchases were rather anomalous, especially the tv.

I just had to change my Amex card because someone tried to make a $10 and $20 charge online. Both charges had been denied because they seemed "unusual." The person I spoke with said it might be something as simple as the security code was requested on the first and they didn't have it, and so the second attempt was automatically denied.

Our company account number was fraudulently used for a while. It was all very small purchases, though, around fifty bucks apiece. So the cc company didn't notice.

But I was pretty sure that my nonprofit company that teaches music to Navajo and Apache kids in Arizona wasn't buying clothes online from a store in Berlin. And if it is, I would like them, please.

The bank initially refunded the money, but then pursued it with the company, so the bank recharged the amounts and the company refunded them. Which fouled up my accounts until I figured out what they'd done, and I feel badly because the company ate the fraud, which I'm pretty sure had nothing to do with it.