We pay for a higher level American Express card and have not had problems with it being "shut off" like a Mastercard or Visa card. AmEx has an international toll free number for me to call them. If necessary they will always accept a collect call. Whenever I leave for a new region or unexpectedly get to a new region - I call and tell them where I am going and approximately how long I will be there.

My AmEx card has worked very well throughout North America (Alaska thru Mexico), Europe, Africa, and Australia - never a problem but that is what I would expect when I pay quite a few hundred dollars a year for their card.

I also have a VISA card and a debit card associated with my financial management account. I e-mail my financial manager when I am going to a new area and he contacts the appropriate VISA folks. The debit card has a daily withdrawal limit of several hundred dollars to limit the exposure to disappearing cash. My financial manager made arrangements with the operations folks that that ensures they will never cut off the debit card unless I call or e-mail. That card is my deep backup when everything else fails.

It took about six-months to get that procedure worked out but now works OK. Initially that VISA card was cutoff when I went from San Diego to La Paz. When I forgot to tell them I was going from Baja to the southern Mexican mainland they cut it off again but turned it back on when I e-mailed them. I did not have to get new cards.

BofA Mastercards and VISA cards are continually being cut off if I don't notify them of "unusual" activity.

I believe this is a 'risk/reward' situation - I risk loosing some cash and possibly credit by having the reward of always knowing that my AmEx card and debit card will be usable. I have only had a couple of occasions (Africa and Mexico) to tell either AmEx or my financial manager that a couple of transactions were bogus. No questions asked - they returned the cash or credited my account.