ANZ Group Holdings (ASX:ANZ, NZE:ANZ), ASB Bank, Bank of New Zealand, and Westpac Banking (ASX:WBC, NZE:WBC), will be required to make sure their open banking systems meet new rules set out by the New Zealand government by Dec. 1, according to a Thursday release from the government.

Kiwibank will be required to meet the open banking rules for payment initiation by June 1, 2026, and for customer account information from Dec. 1, 2026.

The banking sector was designated under the Customer and Product Data Act, which out the rules for how open banking will work in practice in New Zealand.

The five largest banks in New Zealand have begun implementing a voluntary standardized system for open banking, the release noted. The government will draft the regulations and enact them later this year.

Open banking allows third parties such as financial technology firms to access data held by banks on behalf of a customer, with the customer's consent, and they can use that data to develop products and services that traditional banks might not offer.

The government will boost competition in the banking sector to provide greater choice and lower costs to customers, New Zealand's Minister of Commerce and Consumer Affairs, Scott Simpson, said.