I've have on a couple occasions had my card blocked for various reasons, usually when I'm travelling overseas without any out kind of warning from the Bank. The latest example was BECU issued me a new card without warning ( or explanation) while I was overseas ( this was the second new card in one month !!! ) .
And since I can't check my mailbox from half way around the world I obviously don't know my existing card will stop functioning because I can't activate my card waiting in my mailbox.
The bank should send clear and immediate warnings when a card is being blocked or purchases being declined for any reason.
In the most recent incident after calling BECU I was told my card was reactivated my existing card ( which in reality it didn't ) and I told the people whose payment was declined the bank had fixed the issue ( which it wasn't ) which makes me look like a fool or a liar ...
So please if you decide to stop the function of a card immediately notify the card holder. I shouldn't have to chase you down to figure out what's going on.