I've been investigating the issue of whether purchases from retailers outside the UK made using my UK credit cards are covered by section 75 of the consumer credit act. The legal position appears to be unclear, and several sources say that HSBC, Sainsburys Bank and HBOS have all indicated to the OFT that they will voluntarily honour any claims relating to foreign purchases.
One source
I frequently make purchases from abroad and need to know whether my MBNA card affords me maximum protection, or whether I ought to be applying for an alternative card.