New Zealanders are cancelling their travel plans in light of the coronavirus outbreak.

Research by Opinion Compare found that one in five of 858 people surveyed had cancelled or changed their travel plans because of the outbreak.

Seventy per cent were worried that the virus would affect the state of the economy in the next six to 12 months.

Major international events, such as the Formula One in Australia and the NBA basketball series in the US, have been cancelled or deferred.

Auckland International Airport reported on Friday morning that traveller numbers from the start of March were down 18 per cent compared to the same time a year earlier.

But changing travel plans often comes with a cost.

Air New Zealand is waiving change fees for long-haul flights booked between March 5 and 31. People with long-haul bookings made before that date can make one change without a fee, or opt for their fare to be held in credit for 12 months.

Short-haul flights booked between March 5 and 31 can be changed without a fee, but those bought before that will attract a $50 fee, unless they are a Flexi Date ticket, or a Flexi Time ticket changed on the day of travel.

A spokesman said there was less flexibility on short-haul flights because there were fewer flight restrictions on those routes.

Jetstar will allow people who booked between Friday and the end of the month to make one change to each flight within their booking without any fees.

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"We are monitoring the evolving impact of Covid-19 on travel closely and keeping passengers updated on any travel restrictions and options if their flights are impacted," a spokeswoman said.

"To provide customers with greater flexibility and confidence when they book, they can choose a Flex Bundle which gives them the option of a credit voucher if they no longer wish to travel."

Brent Thomas, commercial planning director at House of Travel, said his organisation was having a lot of conversations with people who had planned travel but were now wondering how to proceed.

"There are a few cancellations but there are a lot of amendments because things can be different than they were a day or a week ago."

He said while the number of confirmed bookings being made was down on what it would normally be at this time of year, the level of inquiry remained the same.

People still wanted to plan winter breaks and were aware of good deals in the market, he said, as providers tried to fill the capacity they had.

House of Travel charges $25 per person per one way flight for changes to airfares. Land arrangements have a $65 change fee.

Cancellations attract a $25 fee for domestic airfares and $50 for international, per person per one-way flight. Land arrangements have a $125 cancellation fee per booking. 

Flight Centre revealed on Friday it would close 100 underperforming Australian stores because of the impact of the virus on its business.

Flight Centre charges $50 for changes and $75 for cancellation of domestic or trans-Tasman bookings, on top of the airline or hotel's fees.

Changes for international bookings cost $125 and cancellations $350.

A spokeswoman said, in most cases, when an airline cancelled, travel Flight Centre had waived its own fees. "We're looking at every request case-by-case."

The Government is expected to announce more border measures over the weekend.