Westpac customers are having trouble making payments with some credit and debit cards down.
Newshub has reported customers' cards were declining, despite having enough money in their accounts.
Westpac said it had identified the issue and was working to fix the problem.
"We've identified a network issue that has been affecting all Westpac NZ EFTPOS transactions since around midday. This is affecting debit and credit card transactions at point of sale. This issue may also be affecting other bank cards used at our merchants," it said in a statement.
AdvertisementAdvertise with NZME.
"We apologise for the disruption this may be causing."
Spark is working to fix the network link, a Westpac spokesperson said.
Down Dectector, a website where people can report bank issues, has recieved more 75 complaints in the past hour.