The Vietnamese national currency is the dong, internationally symbolised as VND. Banknotes are available in denominations of 500, 1000, 2000, 5000, 10000, 20000, 50000, 100000, 200000 and 500000 dong. Coins were also introduced in denominations of 200, 500, 1000, 2000 and 5000 dong, although these are rarely seen. US dollars are also widely used and credit cards are widely accepted. Only change money at official money exchange counters with a clear sign showing this status. ATMs are widely available in major cities and tourist areas.
Tipping is not expected in Vietnam, with the exception of bellhops in high end hotels. In any case, the price quoted to you is often many times what locals will pay, so tipping can be considered unnecessary in most circumstances. To avoid paying a tip when a taxi driver, for example, claims they don't have small change, always try to have various denominations available.
Tourists will get refunds of the VAT they paid on goods bought in Vietnam if they are leaving the country from Noi Bai airport (Hanoi) or Tan Son Nhat airport (Ho Chi Minh City). Purchased goods must have invoices and VAT refund declarations issued within 30 days of departure and must be bought from a single shop in a one day duration and must be a value of at least VND2000000.