However, at the end of the day, one is still stuck with a situation where the bank refuses to authorise all transactions until the cardholder has made a phone call to their call centre - this may be impractical or impossible if abroad, and he may not even be aware that he needs to make the call.
Carrying more than one card is the obvious way, and this has saved me from problems many times.
This is just one facet of Citibank's crappy procedures. Another one is this: if you spoil (i.e. not use) more than about 10 cheque numbers over about 5 years (easily done), they put a stop (without telling you) on sending you cheque books. The justification which I got from their monkey (probably in the Philippines) was that somebody could have stolen those cheques and might use them one day.
When I originally went to Citibank, they offered good current a/c interest, £10k overdraft and a £10k VISA card. The last two are now history for any new accounts, and I have to haggle to get them renewed.
I have opened another account now with another bank but who can tell if they won't do the same thing? In this age of robot-staffed customer interfaces, and with anyone (in most firms) with more than half a brain being as distant from the customer interface as they can be moved, and with most firms offering pretty much the same product, what one is really purchasing is customer service.
It's like the endless threads in computer newsgroups about "who is the best ISP"? The physical reality is that an ISP is just a room/building with a load of gear and some fibres running into BT's network, and all the rest from there on is 100% BT. One could make a similar argument for online banking. The only thing that differentiates these firms is customer service.
The problem, increasingly, is that there is nowhere left to run.