The bank closed 38 branches during the height of the Covid-19 pandemic and reduced opening hours at just under 20 other regional branches, as it put the emphasis on call centres and digital services.
Banks closing branches have caused concerns in recent years, particularly in provincial areas. In 2021, mayors from across the country called on the government for a formal inquiry into the matter.
Shortly after, six banks promised not to close any regional branches until at the least the end of that year.
BNZ managing director Dan Huggins said consumer preferences continued to change and it was responding to increasing demand for face-to-face service.
"The feedback we have heard from our customers is that they would like more opportunities to our personal banking experts in our branches, so we are responding to that feedback and giving people access to the experts that they would like."
The extended services would allow for discussions on more complex matters such as housing and business finance, and investments, he said.
The move was not an admission that BNZ had gone too far in cutting services, nor that it had been losing customers, he said, but was a response to changing consumer preferences.
The decision meant there would be full banking services and full banking hours at all branches, but it would not lead to the reopening of branches already closed, he said.
"Four or five years ago there were a lot of branches that customers just weren't using, but where we see demand coming from customers we're certainly open to opening new locations."
The first branches to return to normal hours will be Oamaru and Wānaka in the South Island, and Feilding, Matamata, Te Awamutu, Thames and Te Puke in the North Island.
Last week, the BNZ and the other four leading retail banks committed to no more regional branch closures for the next three years.
