Telstra in Australia has the same network frequency as Telecom NZ on 3G but the only thing to keep in mind is that the phone needs to be unlocked.If you are buying it online there might be a risk.Both the sites show that the phone does have 3G or UMTS 850/2100 so it will work with Telecom but then its the unlock part.Sellers to sell will say that the phone is unlocked but to be on the safe side try and be a 100% sure.