Like most of the rest of the world (excluding USA), New Zealand has the GSM
cellular system. If your cell phone does not work on this system, you may buy
a phone in New Zealand or obtain a pre-paid SIM card or plan from a service
provider.
Mobile phone coverage in New Zealand is very good with all towns and cities
receiving mobile phone coverage from the two main players. However if you plan
to visit the countryside, you must be aware that there are
large areas with no coverage: in many National Parks you are unlikely
to get coverage.
Vodafone is an accepted
provider in New Zealand, along with XT
Mobile Network (Telecom New Zealand) but you might need to buy a specific
phone for using this provider. Vodafone can supply you with a pre-paid sim card
for your phone on a pre pay or Pay As You Go solution.