Air New Zealand says it isn't treating the new Auckland to Invercargill service as a trial and believes it will be a success in drawing large visitor numbers to Southland.

The new service, which begins on August 25, has already sold 11,500 seats since it went on sale in January.

An aggressive marketing campaign in both Auckland and Invercargill has drawn large numbers to the service, which will service the two cities five days a week.

Air New Zealand Head of Regional Affairs Reuben Levermore spoke at an information evening tonight in Invercargill hosted by the Southland Chamber of Commerce, and said the new service was already tracking great numbers.

He said the airline were confident that the route would be a success.

"It is a calculated risk on our part but it's one we're confident about. When we talk about a trial we haven't attached a minimum duration to this. As long as the service is performing it's going to continue. What we want to do is make it so successful that we're not even talking about a trial and that it just continues on. That's where we want to be."

Mr Levermore speaks during the information evening in Invercargill tonight. PHOTO: Ben Waterworth

With the route using a 171 seat A320, the airline was hoping to maintain passenger numbers at around 150 passengers per flight.

"Any service is reliant on performance," Mr Levermore said. "We've been fortunate in the last four or five years that the airline has been growing in line with the economy and in line with tourism that we've had the opportunity to put on new routes. In this case there has been a good business case that's been built, strong advocacy from the Southland community. So we feel the opportunity is here to do it.

"By calling it a trial I think what we're saying to people is that this is new ground that we're breaking and it's really only going to be successful if the community gets behind us and we all work together."

Great South CEO Ann Lockhart also spoke during the event, and mentioned the first steps into bring a direct service between Auckland and Invercargill were first looked into in 2008 when the then Venture Southland conducted a survey which showed strong interest in the service.

A second survey was done in 2017 with the goal of creating a business study which showed similar interest, with the service officially being announced in December last year.

Mr Levermore said the base rate of $79 one-way for the service would remain, and it was important for the service to compete with similar routes coming from Queenstown and Dunedin which already saw high levels of Southland residents flying from due to the lack of direct service from the region.

He said the service would help open up Southland to the rest of New Zealand, as well as opening up the world to Southland residents by creating less connections when it came to international travel.