Barclays has started charging a hidden foreign exchange fee on their Arrival+ (and presumably other cards, as well). I'd used the Arrival+ for some largish transactions in New Zealand dollars last year, and saw that they applied the expected exchange rate for the settlement date as quoted by MasterCard (https://www.mastercard.com/global/currencyconversion/) I did some more transactions in January, but now the exchange rate used by Barclays is around .5-1.0+% in their favor.

This appears to be a violation of their terms and conditions. If you're using Barclays for an large foreign currency purchases you might want to check this for yourself and confirm - the USD amount should match that quoted by MasterCard for the settlement date, which would typically be the next U.S. business day after the transaction took place.

I've confirmed that Citi is still using the MasterCard rates on their cards, at least the Premier.

I've tried contacting Barclays about this but have gotten nowhere, with secure mails just sending me canned responses and live representatives saying they have no control over the exchange rate. Seems like a great class action suit in the making.