Yeah... right...
So if I have taken out the SIM and put a local SIM in, I get all of my credit card transactions declined as an added benefit. Nice...
The identity of the customer in this day and age is no longer the SIM - it is the phone or to be more exact it is the identity for the "Big Three" services on that phone.
Any such harebrained scheme will be reliable only if data is enabled and only if the bank surrenders to the inevitable and asks Google, Microsoft or Apple how would they like it - with hot coffee or with ice cubes. Then it will work with _ALL_ of my household phones including the ancient "spare ones" I take with me when going to the more dodgy places.