Air New Zealand passengers are warned to expect delays.

Air New Zealand says it has resolved a technical issue which affected check-in for flights worldwide.

"Air New Zealand thanks customers for their patience while it has worked to resolve the issue," it said in a statement.

Manual check-in was available at airport counters but customers had been warned they may experience delays checking in for their flights.



Terry Williams King tweeted that the fault caused "chaos" at Auckland Airport.

"Manual check in, long long queues. Staff handling it very well with some grumpy people," he said.

Air New Zealand gold elite frequent flyer member Sean Trengrove said it took him three hours to change a Christchurch to Nelson flight from Wednesday from morning to the afternoon.



Trengrove said he had been trying to change his booking since 6.30am on Wednesday morning but was unable to log in to his Air New Zealand profile using his mobile app or laptop.

"They gave no indication there was a problem," Trengrove said.

He eventually phoned Air New Zealand booking staff who said they could not confirm the flight change.



"Clearly the system had broken down right across the spectrum."

His flight was eventually changed by 9.30am, he said.

Air New Zealand should have posted an alert on its website advising customers of the issue or sent customers a notice directly, he said.



"They have your contact information, why don't they use it?"

Auckland businessman Scott Bartlett said he had a 20 minute delay on a morning flight into Wellington. "So not too bad."

Jetstar spokesman Phil Boeyen said there were no issues with its check in systems.

Were you affected the issues? Email us at newstips@stuff.co.nz