From 30 May, New Zealand’s four major banks - ANZ, ASB, BNZ and Westpac - must offer the secure payment service - although some already have it in place.
It allows customers to give a third party (such as an online retailer) permission to connect to their banking information, meaning there is no need to enter credit or debit card details to make a purchase.
Open banking can be used both on retailers’ websites and on their mobile app, if they have one
It sounds similar to the UK’s open banking system. https://www.rnz.co.nz/news/business/517885/open-banking-how-to-opt-in-and-out-of-the-new-payment-system
I use UK open banking often. I’m always asked to approve the specific access requested, and this takes place at my bank’s website or app. This could be permission to take an amount of money; or for apps which manage multiple accounts (e.g. Emma) this could be all historical transactions; or my accountant uses an open banking service provider (Armalytix) to request transactions for an explicit date range. So far, touch wood, there’s always been an alternative - for example I can use open banking to send my transactions to my accountant or I can manually download a CSV statement from my bank and upload it into their portal.