How can I stop people I'm calling from seeing my number?

Phone companies are required to give customers the option to hide their mobile or landline number when they make a call (Schedule 3, Telecommunications Information Privacy Code [PDF, 315 KB]). 

If your phone company is Spark NZ or One NZ (formerly Vodafone NZ), their websites have information about how you can hide your number:

Spark - Hide your number(external link) (external link)

One NZ - Caller ID for mobile and Wireless Broadband phones (external link)(external link)

If you're with another phone company, contact them for information about how to hide your number. 

You can also hide your mobile number in the settings of your smartphone.

Even if you hide your number, it may still be displayed to 111 emergency services if you call them.