I and my wife intend to visit Hanoi in this summer, and we are wondering something about money. Which currency should we carry? Where to exchange?

Normally you can bring any currency that you want to Vietnam, as long as you exchange that money into Vietnam Dong but USD is the most widely accepted one. You can also use USD or Euro to make payment in Vietnam, especially in hotel, restaurants or some shops in the tourists areas. 

To exchange you currency into Vietnam Dong, there are many ways for you to choose. The first way is to do it right at the airport when you land. You can also exchange currency in any bank in Hanoi, but ANZ bank or HSBC branch are recommended  as they are international banks with better customer service.

You should never exchange currency with the street vendors as their money might be not guaranteed in quality. About international credit card, you can use it in Vietnam to make payment, but there is only limited place, mostly big supermarkets, restaurants, hotel or malls accept this kind of payment. Therefore, prepare enough cash on your purse is more suitable in Hanoi than carry an credit card.