I have 2 bank cards issued in the same country. When abroad in a country A I was using one of them in stores with no problem. And 1-2 times the other too.
One day, in the same country A they both stop to work. In stores it'll throw an error "declined". In ATMs also some other errors -- do not honour, time out or some others. Everywhere, that is. The cards themselves are active, have money, the PIN codes I enter are correct. In the Internet banking of the 2 cards there are no new messages from the banks.
But could they begin to get declined?
I have a 3rd card of a country B. I used it and it did work, on the same day when the 2 cards didn't.
What could be the reason for that?
Note that I'm aware the "a bank might block your card if you use it for 1st time in other country, or in some 3rd world country, etc..." -- this isn't applicable to my situation.