The Bank of New Zealand says it has restored access to online banking services, which had been out of action this afternoon.
The bank said the outage had affected customers' ability to conduct online banking, including the BNZ app, cards and ATMs.
It apologised to customers for any inconvenience while it worked to get the system back online.
On BNZ's Facebook page, one person said it was a "hassle" and they had gone to three petrol stations where their card had been declined.
Another said they were waiting at the checkout line with a trolley load of groceries and no ability to pay.
Another person said such outages happened too often and left customers without access to their funds.