New Delhi, Nov. 5 -- You are buying your favourite Manga comics at a store in Tokyo. The bill for the eight books you have picked comes to Euro8,000. You tap your Indian credit card. The machine shows two amounts: Euro8,000 and Rs.4,800. You think that's great because Rs.4,800 is a number you know and the exact amount that will go on your card statement. So, why not click that?

But you're wrong. The reason is dynamic currency conversion or DCC.

This is a service where the merchant's acquiring bank, which processes credit and debit card payments on behalf of a business-also called the DCC provider-allows the cardholder to pay in their home currency by displaying the amount to be paid right at checkout.

"The exchange rate applied in a DC...