If you drive a light diesel vehicle or any vehicle with a gross vehicle mass of over 3500kg on New Zealand roads, you will need to display a current Road User Charges (RUC) licence. This applies to all vehicles powered by a fuel that is not taxed at source (ie, diesel, electricity).
The most common form of RUC is a Distance Licence. Distance licences are bought in units of 1000 kilometres. The cost of the licence is dependent on the RUC vehicle type (this is specified for each vehicle, based on the number of tyres and axles and whether it is a powered vehicle or a trailer) and the weight of the vehicle, as specified by the purchaser at the time of licensing.