RBS is free up until last Christmas anyway. I have used Natwest also where there was no charge in September last year.
From UB website :
Charges for using your card abroad
Cash withdrawals (Non Euro Transactions)
✓ There is an Exchange Rate Transaction Fee (ERTF) of 1.5% of
the transaction value (except at ATMs belonging to Ulster
Bank, EasyCash, RBS or NatWest).
✓ You will also be charged 2% of the transaction value with
a minimum of of E3 and a maximum of E12 (except at ATMs
belonging to Ulster Bank, EasyCash, RBS or NatWest).
Purchases
✓ There is an Exchange Rate Transaction Fee (ERTF) of 1% of the
transaction value with a minimum of E0.25 and a maximum of E6.
✓ You will also be charged 1% of the transaction value of your
payment with a minimum of E0.25 and a maximum of E6 in
addition to the ERTF
Exchange rates
✓ We apply the exchange rates prevailing on the day we process
your transactions, not the rates prevailing the day you use
your card. Details of commission charges will appear on your
account statement with each transaction. This does not
include any additional fees that a retailer or cash machine
owner may impose on you for using this service.
✓ You can withdraw up to the equivalent of your daily withdrawal
limit in local currency per day provided you have sufficient funds
cleared in your account and provided that the foreign bank does
not impose a local limit.