Samsung Pay has been a hit as compared to Android Pay since it is compatible with both NFC (Near Field Communication) terminals and MST (Magnetic Secure Transmission).
However, as they say, everything has two sides. Samsung Pay also has a negative side thanks to the inclusion of both the technologies. But that is about to change with the latest Samsung Pay update.
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Samsung Pay uses both NFC and MST. While NFC is a new technology, MST is the system which normal debit/credit cards use. Many retailers are still on MST which is okay for Samsung since it has both, but Samsung pay doesn’t know when to switch or not to MST.
Similarly, for terminals that support both NFC and MST, Samsung Pay gets quite confused in selecting the payment method. So at times, disabling MST should help, which is exactly what the latest Samsung Pay update does.
It disables MST, so you could easily use NFC only, removing the confusion Samsung Pay goes through.