Kiwibank said until a postal partner was secured, stores would continue to operate as usual.
Geoff Waller, Kiwibank general manager retail distribution said: "What customers want from their bank has changed.
"Customers want dedicated banking staff, specialist services with private spaces for high-quality banking conversations. Feedback from our customers using our new branch model has been very positive."
The move has not met with approval by all.
Denise Lee, MP for Maungakiekie, said in a Facebook post that the closure of the Ellerslie branch would mean the nearest Kiwibank branches would now be in Remuera, Onehunga, and Glen Innes.
She did not wish to comment further about the post. But others responded with disbelief and anger.
One man said his 87-year-old mother would not have a bank nearby anymore and could not walk to Greenlane.
Another said he had looked at buying into the agency for New Zealand Post and Kiwibank some years back and the costs to buy into the franchise were "incredibly high" compared to other businesses while the returns were low.
"The Government needs to step up and cover the costs of keeping these places open."
Read more:
• NZ Post and Kiwibank split up puts 200 jobs at risk, union says
Waller acknowledged the change was a challenge for some customers.
"We continue to review how we can have presence in our communities in a sustainable way. Standalone Kiwibank branches are a significant investment for us.
"With more and more people every year shifting to alternative banking options and our separation from New Zealand Post, we can no longer sustain multiple sites in close proximity."
He said Ellerslie customers would be able to access banking services from its Remuera branch which would 3kms away or the Onehunga Branch which was 4.8km away.
While Otahuhu customers would be able to access banking services from its new branch when a location was secured.
He said the bank would provide a further update when dates for the changes were confirmed.
The postal workers union Etu has previously warned the split between the bank and NZ Post could put around 200 jobs at risk.
A Kiwibank spokeswoman said there would be no changes to staff until New Zealand Post found a partner to provide services on its behalf.
"When we have confirmed dates for this change, we will consult with our people first and work closely with them and the union to accommodate preferences including redeployment opportunities."
Mark Yagmich, head of retail at New Zealand Post said it was looking for local business to
deliver the postal services and bill payments options that were currently available from the Ellerslie, Otahuhu, Manukau City and Glen Innes NZ Post and Kiwibank branches.
"Whilst we carry out this search we'd like to reassure our customers that there will be no change to our services for customers who use these branches.
"They can still access postal services, such as buying postage and sending parcels, and access the box lobbies."