From 1 April 2017, the way contractors pay their taxes changed, giving greater choice and making it easier to get tax right.
This is an expansion of existing on schedular payments which is the name the tax department uses for payment to contractors like crew that will be subject to withholding tax.
Contractors already under schedular payment rules must complete the new tax rate notification form (IR330C) when you start any new job on or after 1 April 2017.
Tax rate notification for contractors form (IR330C) (external link) — Inland Revenue
On this form, you pick the rate you would like tax to be deducted at. New Zealand tax residents can pick any rate from 10% up to 100%. If you want to change your current tax rate, complete this form and give it to your payer so they can make the changes.
Tax rate estimation tool for contractors — Inland Revenue
This information has been sourced from the Ministry of Business, Innovation and Employment.