Petrol stations around the country are reporting outages at dozens of self-service stations on Thursday morning.
Allied Petroleum and Gull have confirmed the outages on social media saying it's down to a technical error.
Z Energy also has outages on Thursday morning.
"We are aware of an issue with our third-party payment system that is impacting companies across New Zealand today, including Z Energy.
"Unfortunately, this means Z and Caltex customers need to pay in-store at this time as we are unable to process pay at pump transactions. Payment at our truckstop and automated sites are unavailable at this time.
"We apologise to those customers that are impacted as a result of this issue and want to reassure you that we are working closely with our third-party payment provider to resolve this issue as quickly as possible," a Z Energy spokesperson said.
Gull spokesperson Julian Leys said it understands the "frustration our customers are feeling" and will have a discount day next week "to make up for the inconvenience".
Allied Petroleum's fuel stop network is also currently offline, it said.
"Our team is busy working with our suppliers to fix the issue, we will provide further updates as soon as we can," the company said on its Facebook page.
"We're very sorry for any inconvenience caused."
Allied said its manned service stations remain operational.
The station owner of Allied in Pōrangahau, on the east coast of the North Island, told the NZ Herald he had been in contact with head office about the problem, who had told him it was due to the leap year date.
"It's a pain for everyone. They rolled out a new [system] last year but they obviously weren't programmed for the leap year," he said.
Mike Newton, the director of price tracking app Gaspy, said it's had "no reports of pay at the pump not working at manned stations that offer that service in addition to in-store payment".
