I'm wondering how to best take money for our trip and in what currency. Would it be best to takeUS in cash? I would also appreciate other advice re ATM accessibility / functionality; how widely credit card or EFPOS might be accepted?
No worries mate! For you, the Aussie dollar will do just fine. The Tongan currency is called pa'anga but as far as I know it is not convertible, but common currency are the three dollars, AUD, NZ, and U.S, as well as the Japanese Yen, and is rated against those four currencies. One Australian Dollar is TOP 1.85.
Check out the International Dateline Hotel in Nuku'alofa. It is built on the date Line, and while it is Sunday in one end of the hotel, it is Monday in the other end of the hotel. Here is my page on same......have fun.
[original VT link]
Sorry, forgot the ATM issue. Easiest to just give you a page from TripAdvisor, VT's sister site with the information you need, Here it is.