@Josh.mck
The link mentioned by @lameboyadvance - Aus Mobile Network Frequencies under heading "Importing Phones from Overseas"
For full compatibility in Australia with all carriers, it is recommended that you use a phone with the following bands:
3G: 850 / 900 / 2100 [also referred to as 5 / 8 / 1 respectively]
4G: Bands 1, 3, 5, 7, 8, 28, 40.
For 4G, Band 3 and 28 are the most commonly used. If a phone has band 28 available, it is likely to have all the bands you need. the other sections are complex to understand. Just clarifying because 1 / 5 / 8 numbers initially puzzled me :-
