The Commerce Commission proposes to extend regulatory protections for phone number portability for another five years.
Telecommunications Commissioner Tristan Gilbertson said number portability was key to competition because it made it easier for consumers to keep their mobile or landline number when changing providers.
"Thousands of people carry their numbers across providers every week, showing how important the ongoing regulation of number portability is for consumers," Gilbertson said.
The Tech Users Association (TUANZ) said it "absolutely" supported the commission's view.
"Many of us remember the angst and effort that was required when you as an individual or business had to change numbers when moving to a different provider," TUANZ chief executive Craig Young said.
"TUANZ was a huge advocate for its introduction and we have seen the positive impact that it has for users."
Gilbertson said the proposal was essentially unchanged from the current regulatory settings, aside from a suggested change to help facilitate the prevention of fraud in number porting that builds on work currently being progressed by industry body New Zealand Telecommunications Forum.
"Number porting fraud is a relatively new development in New Zealand but has already proven to be of significant harm to consumers," he said.
"It occurs when a fraudster requests that another person's phone number is switched to a sim-card they control, which can then help them access the victim's bank accounts and other important information.
The commission was inviting feedback on its proposal by 26 October, with cross submissions by 5 November.
The current settings expired on 19 December, with the new determination taking effect 20 December.