If you carry overweight loads you can apply for an H Vehicle Type enabling you to carry weights up to the maximum weight under a high productivity vehicle permit at all times (instead of purchasing Additional Licences to cover specific journeys).
You will need to complete a form called "Road user charges application to change RUC vehicle type - RUCCV -H". Please contact NZTA Road User Charges Contact Centre on 0800 655 644 about this.
Vehicles with an H Vehicle Type are required to purchase an H Distance Licence instead of a D Distance Licence for the powered vehicle of an overweight combination. Trailers in the related combination each continue to operate using the appropriate D or B Licences for the related trailers.