Have you ever had trouble swiping your Bank/Credit card at the checkout? Here is a card bag swiping trick for you.

The Problem:
Bank card or Credit card doesn’t work when swiped.

Solution:
Wrap the card in a thin, clear plastic bag and swipe it again.
Arrange a replacement of the card.

What can cause my Card to have bad reads?
The likely problems are dirty or scratched stripe, or erased stripe.

Prevention:
One way to prevent this is to use a thin layer of tape on all your cards from new.

Why does this trick work?
The card reader has a small induction coil that detects a succession of magnetic and non-magnetic zones in the card’s magnetic stripe. When the card is pulled through the reader, each magnetised zone makes a small electrical pulse as it passes the coil. The zones are arranged to encode the data needed to complete a transaction.

The magnetic stripe of your Card is made of fine particles of a magnetisable oxide embedded in a plastic binder. It can get damaged in many ways. When the card reader is reading the card a scratch or other defect in the magnetic stripe can cause a spike in the signal that a too-sensitive reader will interpret as a tick, meaning that the encoded data will fail the parity check and will cause a bad read.

Wrapping the card in plastic bag increases the distance between the card reader head and the magnetic stripe, thus reducing the strength of the signal and smooths out fluctuations and hence the card swipe works.