Figures from the country's four biggest airports show charges for domestic and international passengers can be close to double at one airport compared to another.
The prices are revealed as airports face a new regulatory regime that will do away with wording in law that allows them to "charge as they see fit".
Airport charges - along with other government agency fees - are added to the cost of a ticket and in some cases can be many times the price of promotional airfares.
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The airports surveyed - Queenstown, Christchurch, Wellington and Auckland - are at different stages of their spending cycles and offer varying levels of service through their terminals.
Domestic charges range from $6.06 to $11.98, while international charges range from $12.74 to $23.07.
These exclude expensive extras such as parking fees or the notoriously high prices passengers are charged by airport retailers, especially for essentials.
Other fees imposed by government agencies - not the airport companies - have increased in the past few years and for many inbound tourists a new $35 levy came into force last July.
The highest charge is for international passengers at Auckland Airport . The $23.07 fee, however, is down 3.5 per cent on what was being charged two years ago.
Auckland Airport was last year under fire from the Commerce Commission and faces criticism from airline lobby groups but says its international charges rank approximately mid-way through a group of 26 peer international airports that Air New Zealand flies to.
In the past financial year, passenger services charges earned the airport $185.1 million, up 3.4 per cent on the previous year.
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The airport is now building what it says is one of New Zealand's most important and intensive infrastructure development programmes.
The "airport of the future" is being designed so that by 2045 it can handle double the 20 million passengers who currently pass through its gates.
A spokeswoman says the project is to ensure there will be the capacity to cater for New Zealand's air travel needs, now and into the future.
"We want to build infrastructure that airlines value with fair and reasonable charges, and to further encourage sustainable growth in airline services."
Auckland's ageing domestic terminal is the cheapest in the country to go through.
The company, 22 per cent owned by Auckland Council on behalf of ratepayers, says because of the age of the existing domestic facility, charges there are among the lowest in New Zealand and Australia.
According to the airport's figures, on average, airport landing charges make up between 3 per cent to 4 per cent of the ticket price on a domestic flight.
However, they are set to rise.
"Domestic charges will change when the new domestic jet facility opens, reflecting the size and quality of a brand-new terminal. These charges are yet to be determined, and we will spend at least 12 months in consultation with airlines before any new charges are set."
Domestic charges of $11.98 at Wellington Airport are the highest in the country, while its international charges are $16.98.
The capital's airport has a strong domestic skew. In the year to the end of March, Wellington's total domestic passengers were 5,488,013, while international passengers numbered 929,457.
"Comparing airport charges on domestic versus international is not an apples versus apples comparison. This is due to a number of factors including the aircraft and passenger mix at airports, terminal configuration and usage, the stage in pricing period," a spokesman said.
Wellington, Auckland and Christchurch are subject to a light-handed form of Commerce Commission regulation called "information disclosure" over five-year periods.
The commission says this "shining a light" on the airport's pricing and spending decisions is to improve transparency about their performance.
Wellington Airport is 34 per cent owned by Wellington ratepayers; the remainder is owned by utilities investor Infratil.
The spokesman said, when taking inflation into account, its charges had been flat over the past five years.
''We've also recently completed a major upgrade to our main terminal which has seen new pop-up food and beverage outlets showcasing local and international favourites, continuing to lift customer experience.
"Over the next year there will be further improvements to the dining and retails areas."
In the year to the end of June, Christchurch Airport handled 6.93 million passengers, up 65,000 on the previous year and aircraft traffic was up 2 per cent.
It charges an average of $9.68 for domestic passengers (averaging turbo prop and jet) and $12.74.
While the commission last year took a swipe at Auckland Airport's charges (leading to a $33m reduction in the current period), it said charges by Christchurch were "reasonable and consistent with promoting the long-term benefit of consumers".
The airport is 75 per cent owned by Christchurch City, the remainder is held by the government and says the passenger prices are charged per travelling passenger - there are no weight-based aircraft charges or charges for empty seats at Christchurch - aligning airport charges to a ticketed/occupied airline seats.
"This makes it easy and transparent for the travelling public and airlines to understand the exact per-passenger price for usage of airfield and terminal assets at Christchurch," an airport spokeswoman said.
Queenstown Airport is 25 per cent owned by Auckland Airport and 75 per cent owned by the Queenstown Lakes District Council.
It is the fourth busiest of the airports surveyed and charges $8.94 (averaging turbo prop and jet) for domestic passengers and $19.21 for international passengers.
About a quarter of its 2.3 million passengers are on international flights.
The Board of Airline Representatives (Barnz) has 28 airline members and five non-airline members.
Its executive director, Justin Tighe-Umbers, says changes to the Civil Aviation Act due in 2020 would remove some archaic hangovers in current legislation covering airports.
"Most importantly for airlines it will remove an old clause, section 4A in the Airports Authorities Act, which states 'airports can charge as they think fit'."
The association says this is a greenlight for airports to overcharge passengers through the resulting effect on airfares and also through the use of airport infrastructure like parking.
"New Zealand's airports are monopolies. They hold the power in commercial negotiations with their customers. Barnz thinks the current Act helps tip the balance even further," Tighe-Umbers said.