Unlocked or unbranded. One is that you can use another mobile phone provider sim and the other is having nothing but EVR in the Service Provider software version which means it has original Samsung software and not service provider specific (ie Vodafone, EE, I etc.) software.
Also, pretty much all banks support Samsung Pay off you get a free Samsung Pay card as it sits as the middle man between your back card and the app. Had other bandits too. Provided by Curve.
Branded is down to the service provider software and not the company you bought from as sometimes companies will provide unbranded handsets when asked specifically. You have to be very clear with them as to what you want at point of purchase. Got unbranded from Vodafone in the past, but not managed it for a long time.
I checked this with my bank customer care dept and they informed me that they have stopped supporting Samsung pay so any new cards won't work they said they were focussing on Google and IOS and not supporting any more apps at this stage and they said other banks are moving in same direction so I presume it's to save costs but worth checking with your own bank to make sure
Natwest never opened up to Samsung Pay app, but if you get a Samsung Pay card via Curve you can associate it to your Natwest account/card and associate the Samsung Pay card with the Samsung Pay app.
