You swipe your credit card as you’ve done so many times before — but, for some reason, it’s not working. You hand the card over to the cashier to swipe; and they have no luck processing your payment using the magnetic strip either. Have you ever encountered this problem and wondered why the credit card chip is not working or your card won’t swipe?

You know your account is in good standing, and maybe the card even looks fine. So why does a magnetic strip or a chip on a credit card you’ve used for a while all of a sudden refuse to cooperate?

Consider these potential causes for why your credit card won’t swipe:

  1. Your card is dirty.
  2. Your purse or wallet uses a magnet.
  3. Your card and your mobile device travel together.
  4. Your card was near a security sensor removal device.
  5. You brought your card into a room with an MRI machine.
  6. You scratched or disfigured the strip.
  7. Your card overheated.
  8. Your card has an embedded chip.

1. Your card is dirty.

Your card’s chip or strip gets a little dirtier with every surface it encounters; eventually the buildup of grime may mean your credit card won’t swipe. Though some credit card users have brought their card’s swiping functionality back to life by applying and removing a piece of adhesive tape to remove debris, it’s not a guaranteed solution — and could scratch the strip permanently. Others have suggested using a dollar bill to clean the chip.

2. Your purse or wallet uses a magnet.

The strip on the back of your credit card, and the information it contains about your account, uses magnetic particles in its swipe functionality. Contact with magnets can essentially scramble the data on a card’s magnetic strip. Once that happens, point of sale terminals can’t “read” the card.

You may not see magnets in your purse or wallet, but they’re a common design feature used to facilitate opening and closing. Your card’s swiping ability could be compromised if your purse or wallet uses magnets and your card’s strip comes close enough to them for an extended period of time.

3. Your card and your mobile device travel together.

The materials used in some card’s magnetic strips are simply more susceptible to damage than others. If you happen to have one of these more sensitive strips (called low coercivity or LoCo) on your card and place it in direct contact with a mobile device for a long period of time, it could affect your card’s ability to swipe. These days, LoCo stripes are becoming less and less common as most cards move toward high coercivity (HiCo) technology.

4. Your card was near a security sensor removal device.

Retailers often attach security sensors to items they sell in-store to deter theft, but some of the devices that are used to remove the sensors at the point of sale can affect the magnetic strip on a credit card placed close to them.

5. You brought your card into a room with an MRI machine.

Have you had a recent medical office visit that put you in close proximity to an MRI machine? That could explain why your credit card won’t swipe. The magnetic forces used in MRI procedures are so strong that your card could lose its ability to swipe just by being in the same room as an imaging machine.

6. You scratched or disfigured the strip.

Carrying your credit card in your pocket with keys or coins can scratch the card’s magnetic strip, making the swipe feature unusable. Likewise, your credit card won’t swipe if the strip becomes bent or cracked to the extent that the data on the strip becomes distorted.

7. Your card overheated.

If you bring a credit card along on a hot summer day to the beach or pool, a few hours in extreme heat could distort its magnetic strip so that it won’t swipe. Bringing your credit card into a hot yoga class could have a similar effect.

8. You need to use the chip first.

Chip cards have been rolled out by credit card issuers and banks in order to enhance payment security, and when you try to swipe these cards at terminals that are fully enabled for chip cards, otherwise known as EMV, the terminal will prompt you to insert your card with the chip facing up and the chip going in first into the terminal instead. Cards with chip-and-PIN and near-field communication (NFC) technology typically aren’t vulnerable to magnetism the same way magnetic stripes are.

The bottom line: If your credit card won’t swipe, contact your card issuer for a replacement card. You may also want to consider a contactless card or using mobile payments.

Published December 21, 2016.

Updated September 14, 2020.

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