Originally Posted by NickB

AAUI, it is primarily relevant for those with accounts at banks that charge for use of ATMs outside their network. It is a non-issue with UK-issued cards as, AFAIK, no UK bank charges for use of ATMs outside their network. This is not necessarily true in all countries, though. For instance, I also have an account with Societe Generale in France and, while they won't charge me for cash withdrawals at ATMs within the Societe Generale Group, they would charge me a fee for a cash withdrawal from an ATM in a bank outside their own network (they allow me 3 such withdrawals per month but would charge me a fee from the 4th onwards). AIUI, arrangements such as those described by NWIflyer allow for fee-free withdrawals within the extended network for those kinds of banks.