Currency and ATMS
The currency used in Vietnam is the Vietnamese Dong. US dollars are also accepted and used. At the time of writing, 1 GBP = 29,780 Vietnamese Dong and 1 USD = 22,733 Vietnamese Dong. Be careful when handling Vietnamese money: the lowest and highest note is the same colour. Some locals will take advantage of this with travellers, accepting the highest notes and returning the lowest. ATMs are everywhere, even in the small towns. It is recommended to pay for your travel with cash. Some places will accept card payments, but this is in high-end restaurants and hotels.
Standard of Living
Your money will go far in Vietnam. A glass of beer costs 40p/$0.50. A bowl of noodles around £1.50/$2. Local transport costs around 80p/$1 and sleeping in a cheap hotel or dorm costs around £4-£12/$5-$15. Massages cost around £5-£15/$6-$20 and taking an internal flight in Vietnam costs around £23-£75/$30-$100.
Tipping in hotels, taxis, restaurants and bars is not expected. It is kind to tip a local guide if taking a day trip however, with a couple of dollars for each day.