MST was great, but its death is a good thing for mobile payments

Think back to a time before tapping your phone to a register or vending machine was a real thing that people did every day. In those days, you used a credit card, or you hoped that you went to a store that supported one of those new NFC terminals that only worked half the time.

If you used a Samsung phone with Samsung Pay, however, it didn’t matter where you shopped. You could always pay with your phone. It used a technology called MST (Magnetic Secure Transmission), which basically lets your phone be read like any credit or debit card that uses a magnetic strip across the back of it.

MST works by generating a magnetic signal very similar to a credit card’s. That magnetic signal is then transferred to almost any payment terminal with a card reader. If a terminal can use your debit or credit card, it can use your Samsung phone with MST. It’s just one of those magical hacks we take for granted.

Then along comes the Galaxy S21 without MST and all that Samsung had built was seemingly torn asunder. But not really.

MST was one of those features that came about just when it was needed. It’s now been killed off because it’s no longer needed.

Your bank hates any sort of magnetic stripe payment reading and any recent card you’ve been issued probably has some sort of tap and pay system like NFC or chip-and-PIN. That’s because your bank hates paying out money for fraudulent payments, which are more likely to happen when shooting magnetic signals around to terminal and card readers and skimmers than it is to happen with close contact systems like NFC. Samsung prefers NFC payments because credit card companies and banks prefer it, and that means more of them are likely to participate in Samsung Pay.

Of course, that means whatever you’re trying to give a digital representation of your cash to also has to support NFC or chip-and-PIN or ESP or whatever your bank thinks is best. That’s the rub because it puts us back to square one in many places where NFC payment systems just aren’t available in any sort of numbers.

I know this because I am not an average tech blogger who lives in New York. I’m just some guy who lives a relatively quiet life in the woods along the Appalachian Trail. I can use NFC payments at a Jamba Juice machine in front of GameStop. But I can use MST technology to buy — and I am being literal here — minnows and fishing worms at a buddy’s store nearby. MST is still useful where I live, but in most larger cities, retailers have largely adopted tap-based payments. It’s the future.

It makes sense that banks want to use the most secure method possible to handle point-of-sale transactions. It makes sense that Samsung is at a place where it’s ready to ditch older technology to lower liability for its partners. It even makes sense that corporate giants like Chase aren’t rushing to provide chip-and-PIN terminals to stores atop the Blue Ridge Mountains. That doesn’t make things more convenient for everyone, though.

The great news is that you can continue to use Samsung Pay through MST from certain Galaxy Watches, and most flagship Galaxy phones before the S21, including the Galaxy S20 FE, still support it.

The other great news is that if you need some bait, I know a guy who accepts MST payments, and you get some pretty great fishing in the process.