How to Fix a Stubborn Credit Card
By Chad Upton | Editor
Have you ever worn out a magnetic card? You can ask your bank for a new one but it usually takes a few days. In the meantime, you can put a piece of clear tape or use some receipt paper from the cashier to cover the magnetic stripe while the card is swiped.
Usually, the cashier will do this for you, but if not then you can ask them to try it. Some may even use a plastic bag, but any thin barrier may work. Be sure it’s very thin so it doesn’t get jammed in the card reader.
Many people know about this little trick; the real secret is why it works…
As a magnetic card gets used, the magnetically charged particles get smeared. This smearing repeated many times creates magnetic noise which distorts the data when read. The magnetic strength of the noise is low enough that a small barrier can block or reduce it enough to get a proper reading from the card.
For a bit of anecdotal evidence, I worked retail back in college and I used this trick hundreds of times — it worked nearly every time.
Sources: creditcards.com, wired magazine (Nov 2011)