Strange situation. A few months ago, my bank debit card expired, card A. I put in an order for a new one and got it quickly. I’ve been using that card for the last few months, card B.
This week in the mail, I get a debit card (same bank, same type, different number, card C) saying “here’s your card to replace card A”… but card B had already replaced card A.
Figuring they just made a strange mistake and that I’d just destroy card C and keep using card B. I didn’t actually destroy it yet, I just put it aside. Anyway… I go to the store and want to buy something. The guy runs the credit card (card B, the one I’ve been using for months) through the machine and the machine can’t read it. The stripe isn’t giving the data, like it was a damaged card… but there was no damage as far as I can tell. He tried another reader, no response. Eventually he had to imprint me.
So my question: When banks cancel a card, do they have some method of remotely deactivating the magnetic strip on the card? Maybe through their ATM machines? If not, why the hell did my card stop physically responding to readers?
I called up the bank and they say both C and B are active, but B has since had internet purchases declined on it, and C requires activation through using as an ATM card, and I don’t have the pin. Great. I also ordered some e-tickets from an airline on card B… and I was going to use one of those kiosks to retrieve my ticket, but now if the magnetic strip on that card doesn’t work… I can only hope they can help me at the counter, I guess.
The machines read the numbers recorded in the strip and compare it with the number(s) stored at the bank. If the numbers do not match (or the number on the card reperesents an invalidated card) the machine rejects it. The banks can’t alter the magnetic strips. Only read them and say “that card is invalid”
Card A has a number = 123. Bank has the number 123 associated with that card.
You get a new card, card B. On card B is stored 456. The bank records on your account that your card is now 456 and that 123 is your old card and no longer valid.
Same goes for card C (789) so card B becomes invalid. Your bank now has ‘789’ as your card.
You put card B in the machine. The machine reads 456 and then asks the bank what your number is. 456 is not equal to 789 so the machine ‘fails’ to read your card.
Right, I understand how the comparison works. And the cashier might not have known how his system worked, for that matter.
When I worked as a cashier, when the card was swiped, the card number would appear on the screen. Then, if it were declined, the screen would say it was declined. But if you had a damaged card, with an erased magnetic strip, it wouldn’t scan at all. What appeared to be happening was the latter case - the card simply wasn’t scanning, not that it was scanned and rejected. However, their machines probably work differently and the cashier didn’t understand the difference… so maybe it was just silently declined.
I work with mag stripe cards every day and have had reasonable dealings with banks.
I think the failure of card B was a coincidence rather than a planned action by the bank. mag stripe writers for hico cards (most every durable card handed out these days) are quite a bit more expensive than readers for same. They also use a fair amount of power. These two facts together make it very unlikely that any device you regularly present your card to is capable of blanking the stripe. I bear correction from somebody more familiar with US ATMs but I’m reasonably certain of this.
As to why your card stopped responding, there are numerous possible explainations, without seeing the card and testing it I couldn’t tell you what happened, but I’ve seen cards that looked perfectly alright to visual inspection fail to read entirely in one reader but be fine in a different model of reader (normally because the encoding device was out of alignment).