How to Repair the Magnetic Strip on Your Bank Card

Though most banks and credit cards work with computer chips and contactless payment, they still have those traditional magnetic strips, which can get damaged. Can you fix the magnetic strip on a credit card? The answer is maybe, but only if it is scratched.

The writers at Money Management International explain how to ruin the magnetic strip on a credit card. Though credit cards can last for years, they do not hold up well to water, and this can cause the card to stop working. The strip is also vulnerable to other magnets if those are large (think MRI machines). So whenever going in for these tests, be sure to leave your wallet in a secure location elsewhere.

Magnetic strips also get scratched, which is probably the main reason why they become unreadable. If you accidentally signed a credit card on the magnetic strip or it got knocked up against something, it could get ruined. Dirt could also be a culprit; if the magnetic strip is covered with enough debris, the card reader might not be able to work. Of course, the problem could also lie with the card reader, since readers often malfunction.

Magnetic strips are not only used on credit cards. If you have checked into a hotel during the past decade, you were probably given a key card with a similar kind of strip. According to Science ABC, these strips are made out of small iron-based, magnetic components. They compare it to magnetic recording tapes that record information. The strips are encoded with information when their particles are magnetized in different directions.

When inserted into a card reader, a reader head creates voltage that is electronically recorded and read by a processor or reader. This authenticates the user and the transaction. Though credit card and hotel key magnetic strips work differently, both can be damaged in similar ways.

If the magnetic strip suffered water damage or was demagnetized from an MRI machine, it most likely will not work again. There are ways to fix credit card magnetic strip damage though, at least temporarily. The writers at CardSource explain that some checkers use plastic bags to cover up the strip when cards don't work. The plastic can work to mask the scratches, but the bag needs to be held tightly against the magnetic strip.

A card scanner can also look over the scratches if they are covered with masking tape or a slim piece of paper. This could come in handy when you are at a register and need to make the purchase with your card but make sure to slide the card in and out quickly. It may take the card reader longer to work, though. This trick may be less likely to work at ATMs and other locations where the card goes into the slot and stays there before being returned.

Consider yourself lucky if you are able to complete the transaction with a scratched magnetic strip. It may not work the next time. The best advice is to contact the credit card company or bank as soon as possible, and they will be able to send out a replacement card.