BNZ will close eight of it branches on Christmas Eve and 30 more before the middle of next year.
Chief customer officer Paul Carter said about three-quarters of its customers bank online or over the phone and the physical branches simply did not attract customers anymore.
"The majority of our customers are banking online and our talented bankers are often waiting in empty branches for customers who simply do not arrive."
He said the company would help affected staff find new jobs.
"We have great bankers in our branches and we will be working with them all to find new job opportunities at BNZ, irrespective of where they are based."
Carter said COVID-19 had accelerated the trend of customers banking digitally.
"Branches will still have a role in how we serve our customers. We will continue to invest in modern customer centres to help customers take advantage of online banking and our digital tools, and where they can access specialist services."
The bank would retain just over 100 branches, nearly 400 smart ATMs, three mobile BNZ branches as well as its contact centre and digital services.
"Our mobile branch worked well in the Manawatū-Whanganui and Northland regions bringing banking services and financial support to remote communities, and we will be adding additional vehicles to our fleet to enable more communities to receive financial support."
Branches to close on December 24, 2020 (8 branches):
Branches closing between February - March 2021 (14 branches)
Branches closing between April - June 2021 (16 branches)