Do magnets break contactless cards?


Do magnets break contactless cards? Instead of a magnetic strip that you swipe, most credit cards now have an EMV chip that you insert into a card reader or even use to pay contactlessly. Luckily EMV chips aren't affected by magnets. However, scratches or prolonged exposure to water can cause damage or make them stop working altogether.


How strong does a magnet have to be to damage a credit card?

The magnetic strip on credit cards come in two varieties. The high-coercivity ones, like a typical credit card, require a field strength of somewhere around 4,000 gauss to demagnetize. The low-coercivity ones that are often re-written, like hotel keys or gift cards, require about 300 gauss.


Do hotel key cards demagnetize?

There's a number of reasons keys can become deactivated. Most cards are magnetic strip swipe cards, and can become demagnetized. The most common reason for a room key to get demagnetized is the use of cell phones.