BNZ says its online banking service is back online after an outage this morning.
It is the second outage this weekend, following one yesterday afternoon.
Hundreds of people reported that they couldn't access BNZ between 9am and 12.30pm today.
Customers expressed their frustration on social media, saying the recurring outages were not good enough.
BNZ said some customers might still have issues logging in.
In a statement to 1News earlier on Sunday, a BNZ spokesperson said the bank was affected by an outage as a result of an issue experienced by a network provider.
It apologised to customers for any inconvenience.