The Electricity Authority says 396,376 households switched electricty retailers in 2013, compared with 356,881 in 2012, an increase of 11 per cent.
The average annual household saving from making the switches was $155, the authority said.
Authority chief executive Carl Hansen said it was good to see New Zealanders exercising their choice to switch electricity companies in a bid to realise cost savings and other potential benefits such as reward points.
Looking for a better power deal was part of maintaining a competitive market, he said.
Checking potential cost savings and benefits from switching power companies was worthwhile as retailers offered different deals to attract different customers.
"Checking also doesn't have to mean switching - we are seeing more retailers offering discounts as an incentive to stay with an existing supplier," he said.
"The key is having informed customers with the ability to choose a deal that best suits their needs."
Hansen said the What's My Number online tool, which was run by the authority and Consumer NZ, allowed consumers to check what deals were available.
The authority had heard reports of clients being offered between $80 and $300 a year in discounts, which gave them a price reduction ranging from 3.7 per cent to 13.8 per cent for an average residential customer, he said.
What's My Number spokeswoman Judy Bailey said now was a good time to review electricity providers as winter began to bite.