From Thursday, customers will be able to securely share their banking data with approved third-party services, including budgeting apps, lenders and payment providers, through Kiwibank's internet banking and mobile app.
Open banking allows people and businesses to connect their bank accounts to other financial services, with customer consent, making it easier to manage money, make payments and access more personalised products through secure systems that allow services to share data.
Kiwibank said it was not intending to charge fintechs - who develop open banking applications - to access its systems.
Kiwibank chief customer officer Mark Stephen said the move was about giving customers more choice and helping foster innovation in the financial sector.
The bank was initially partnering with local fintech company Wych, to connect Kiwibank with accredited third parties securely.
It was also working with local fintechs Akahu and Volley to deliver open banking services, with plans to expand the number of providers as the system developed.
Stephen said the "open" in open banking reflects the potential for new services that did not yet exist - but that customers would be able to connect to them easily when they did.
Businesses were expected to be among the early adopters, with open banking tools offering the potential to automate processes, improve cashflow management and streamline payments and compliance.
Kiwibank said customers would remain in control of how their data is shared, and with whom, with consent underpinning every connection.
The rollout comes ahead of regulatory deadlines, as New Zealand's banking sector moves towards a more open data environment aimed at boosting competition and expanding the range of services available to consumers and businesses.
