I am in the UK and thinking of buying an S7 to bring home to NZ and seek a refund of the VAT. I understand how the whole VAT refund thing works but I remember some years ago you had to be careful buying overseas to make sure the phone had the correct mobile network bands so that it would work in NZ. Is this still the case - it's something I know nothing about. If I buy an S7 from say, Carphone Warehouse, how can I be sure it will be compatible with NZ networks?

Thanks in advance.