Air New Zealand is cracking down on record numbers of unruly passengers who are verbally or physically abusing staff.

The airline has taken action against a growing number of abusive passengers during the past year - including imposing a five-year ban.

The airline has issued a record number of warning letters and bans during the past year and is urging passengers to show respect for each other - and airline staff - over the busy summer season.

Tomorrow is the busiest day of the year as more than 60,000 passengers head away on more than 600 flights across Air NZ's network.

The airline's chief operational integrity and standards officer David Morgan said more bad behaviour was stemming from passengers drinking too much.

"We're seeing more instances of customers trying to over-indulge in alcohol in lounges or in-flight," he said.

"The upshot of the poor behaviour is that we have issued 15 per cent more warning letters to customers this year - and seen a 60 per cent lift in the number of customers who have been banned from travel on the airline for between one and five years," he said.

The airline could not release numbers due to "commercial sensitivity" but it would be a small fraction of the 17 million passenger journeys the airline provides every year.

While the number of flights has increased in the past year, that growth is far exceeded by a rise in the number of travel bans.

"We want all our customers to have an enjoyable experience and won't tolerate poor behaviour toward each other or our staff, who try to go the extra mile to deliver a world-class uniquely Kiwi experience."

Earlier this year two passengers were kicked off an Air NZ flight before take-off from Wellington to Auckland after reportedly refusing to pay attention to an airline safety briefing. In another incident a man was removed from a plane that landed in Hamilton after disruptive behaviour.

The airline has also been taken to court by a Nelson lawyer after it banned her from travelling with it for a year, when a dispute about entry into a Koru Lounge escalated.

Under its conditions of carriage the airline can order a passenger be offloaded, prosecuted and banned for failure to comply with any instructions of the crew for smoking, alcohol or drug consumption or behaviour likely to cause discomfort, inconvenience, damage or injury to other passengers, the crew or any property,

Crew have the power to restrain passengers.

Civil Aviation figures show there were 28 unruly behaviour incidents between September last year and August this year, 30 cases of smoking and 17 intoxicated passengers reported.

The issue is escalating around the world, with the International Air Transport Association reporting that there was an incident of unruliness on one out of every 1053 flights in 2017, up from one in 1424 flights the year before.

The union representing 8000 aviation workers here, E tū , says it is aware of the issue and is calling for kindness these holidays.

"Peak times, disrupts and delays are frustrating for everyone but its important not to take out your stress on the airport and airline staff," said the union's head of aviation, Savage.

"Please spare a thought and share a smile with all the hard working airport and airline workers working to get us safely to our destinations on time," he said.

The union is advising passengers to give themselves extra time to get through crowds and "even take small gift to pass to your busy flight attendant or gate agent. A little kindness goes a long way at this time of year".

Air New Zealand general manager of Auckland Airports Todd Grace is advising travellers to allow additional time to get to and through the airport they are travelling from.

"Naturally airports are going to be much busier than usual so we're asking customers to be as patient as possible as our staff both on the ground and in the air work to get everyone to their holiday destination.''

Passengers should take out travel insurance so they were covered in any unexpected situation and were encouraged to sign up to Air New Zealand's Travel Alerts service in case the airline needs to make contact with them in the event of any travel disruption.

Air New Zealand's busiest route will be the Auckland–Christchurch service tomorrow.