For instance we are assuming that the Debit Card or Credit is issued by an Indian Bank. In case of an Indian Bank INR or Indian Rupee is the default currency and the card will be charged in INR only. To activate international transaction on this card or to use this card in any currency apart from INR, we have to activate International Transaction from the issuer bank. Few bank pre activate International transaction on your cards and in few bank we have to activate it by visiting a branch/ calling the customer card or from online banking. Few banks don't provide the service of International Transaction on their Debit Card and these cards cannot be used in any International transactions. These debit cards don't have a provision to be activated for any kind of International transaction. Customers have a choice to upgrade these kinds of Debit Cards to a International Debit Card (If bank have this feature).
Things we should keep in mind before doing an international transaction
Check whether International Transaction is activated on that card or not
You have sufficient limit or balance on your card or account before executing the transaction. (Example- You want to do a transaction of 1$ and current value of 1$ is Rs. 70. Let say your bank is having a international currency conversion fee of 5% then the currency conversion fee for 1$ according to current rate will be Rs. 3.5. Apart from this 18% GST on Currency conversion fee i.e Rs. 0.63 in this case will be charged. If we will sum up all these rate, fees and tax then the total amount is Rs. 74.13. So, you should that 74.13 in your bank account or credit limit to make a transaction of 1$ as per assumed rate, fee and tax)