Depends where you are wales 1. The only place I found it difficult to change AUD cash to Dong was in Hanoi, I always end up using the ANZ by the central lake near the old Quarter.
Saigon or Ho Chi Minh City there are money changers were about, check rates as you go as they vary.
In the Highlands like Dalat and Sapa make sure you have Dong with you, I didn't ever see an ATM out there...but then never looked for one either.
Places like Hoi An, Da Nang, Nha Trang you will find money changers here and there or an ATM.
But I always make sure I have local currency in cash if going to the out of the way places.
