How to Prevent and Fix a Demagnetized Credit Card

A credit card’s magnetic stripe, often called a magstripe, is a thin band on the back of the card that stores digital data. It contains essential information like your account number, name, and expiration date, allowing card readers to process transactions. A “demagnetized” card means the data on its stripe is corrupted or lost, rendering it unreadable by payment terminals. This condition is not intentional, but a result of external factors affecting the stripe’s magnetic properties.

How Magnetic Stripes Lose Data

Credit card magnetic stripes can lose their data through several common mechanisms. Strong magnetic fields present a threat, as they can disrupt the encoded information on the stripe. Items like cell phone cases with magnetic closures, refrigerator magnets, or even security tag deactivators at checkout counters can interfere with the magnetic particles if in close proximity. While a single, brief exposure to a small magnet might not cause immediate damage, prolonged contact or exposure to very strong electromagnetic fields, such as MRI machines, can corrupt the data.

Physical wear and tear also contribute to data loss on magnetic stripes. Each time a card is swiped through a reader, or rubbed against other cards, keys, or coins in a wallet or pocket, the stripe can experience friction. This repeated abrasion can lead to scratches, dirt accumulation, or general degradation of the magnetic material, making it difficult for readers to retrieve the necessary information. Over time, bending the card or rough handling can also physically damage the stripe, impacting its functionality.

Extreme temperatures can affect the magnetic stripe. Leaving a credit card in direct sunlight or inside a hot car can cause the card material to warp. This physical distortion can, in turn, damage the magnetic stripe, preventing it from being read. While less common than magnetic interference or physical damage, heat exposure remains a potential cause for a card’s stripe to become unreadable.

Preventing Magnetic Stripe Damage

Protecting your card’s magnetic stripe involves mindful handling and storage. To prevent issues from magnetic fields, store your cards in a wallet or cardholder with dedicated slots, keeping them separate from strong magnets. This includes avoiding phone cases with magnetic closures, magnetic money clips, or placing cards near speakers, which generate magnetic fields. If your bag or wallet has a magnetic clasp, position cards so their stripes face away from the magnet.

Careful handling is another measure to preserve the stripe. Avoid bending the card and keep it away from abrasive surfaces or objects like keys and coins that scratch the stripe. When storing multiple cards, ensure their stripes do not rub against each other, as this friction can lead to wear. Using a protective sleeve can shield the stripe from damage and dirt.

Being aware of temperature extremes can extend the life of your card. Do not leave cards in places exposed to high heat, such as on a car dashboard or in direct sunlight. Excessive heat can cause the card to deform, which can compromise the stripe. Keeping cards clean by gently wiping the stripe with a soft cloth can prevent read errors from dirt or debris.

What to Do If Your Card Stops Working

If your card’s magnetic stripe stops working, begin by attempting to use the card at a different terminal or location, as the issue might lie with the reader itself. Gently cleaning the stripe with a soft cloth can sometimes resolve superficial issues caused by dirt or grime. There is no consumer method to “re-magnetize” a card, as the process requires specialized equipment.

When troubleshooting does not resolve the issue, contacting your card issuer is the next step. You can find the customer service number on the back of your card, on your monthly statement, or through the bank’s website or mobile app. When you call, be prepared to provide your account details and explain your card’s magnetic stripe is unreadable due to damage.

The card issuer will guide you through the replacement process. For damaged cards, they usually issue a new card with the same account number. Replacement cards typically arrive within 5 to 10 business days, though some issuers may offer expedited shipping for a fee, delivering a new card in as little as one to three days. While awaiting the physical replacement, some banks offer temporary digital card access via mobile apps, allowing you to continue making online or digital wallet purchases.