More than 1500 travel delegates from around the world are descending on Ōtautahi for the country's biggest tourism business event.
The industry says it's an event that will help to shape the country's tourism economy for years to come.
TRENZ was last held in person in 2019.
It has been 17 years since Ōtautahi has hosted the event, back in 2006.
ChristchurchNZ destination and attraction general manager Loren Heaphy said it has not been from a lack of trying.
"We were supposed to host in 2011. For obvious reasons, we were unable to. Again, we were supposed to host in 2020, but went into Covid lockdown about three weeks before we were able to host TRENZ, so we're finally about to host this massive event."
ChristchurchNZ expects the city will benefit from a visitor spend upwards of $2.5 million from TRENZ at Te Pae.
"Having business events like this which are mid-week in the low season when it's a quieter period of time means that our bars and restaurants will be humming, retail, shopping will all be buzzing."
A welcome event was held at Te Pae on Monday night with TRENZ kicking off in force on Tuesday.
Tourism in the city has been recovering well.
Pre-earthquake, the city's international visitor spend was about $1.75 billion.
That took a hit as the city recovered and rebuilt, climbing back to $1b not long before Covid struck.
Heaphy said they were sitting at roughly $1.25b after a great summer season, and hosting TRENZ would make a big difference.
"These travel agents will be making decisions around people coming to our city for the next five to ten years. It will improve things like our airline connectivity, our hotel occupancy, our retail, hospitality.
"The legacy outcomes are absolutely huge from this event."
ChristchurchNZ predicts about half a billion dollars a year worth of business will come into the city from visitors from those travel agents.
It will be Nicole Ellwood's first TRENZ with her business Crater Rim Walks that operates in the hills around Christchurch.
The event at Te Pae was a huge opportunity for her small, family-run business, she said.
"To date, we've had most of our bookings come through online travel agents ... and what we haven't had the chance to do is actually connect with and meet face-to-face some of the overseas travel agents who will be able to sell our product."
The business went into hibernation when Covid first struck.
They've since had a bumper summer season after reopening, and she said they were looking to expand.
"We are really lucky to be hosting a couple of famils so not only will we be meeting people through scheduled appointments.
"But we've also got the chance to actually showcase our product and take people out to the hills which we love and showcase our beautiful coastline and the Lyttelton Harbour and actually show them what we've got to offer."
Tourism Industry Aotearoa chief executive Rebecca Ingram said TRENZ would help to build back the sector's momentum.
"TRENZ is a really important milestone in the calendar of tourism. But it's also where the business gets done for years out.
"So the conversations and business that will be done at TRENZ this week is going to make a difference for those businesses and the New Zealand economy for years to come."
While the industry had benefited from a strong summer, that growth had reached a plateau.
Ingram said they always expected it would take two to three years for the industry to find its new normal.
"The DNA of the tourism industry has forever changed as a result of Covid. There are new ways of operating. There are new ways of delivering our products and services, and there has been an opportunity for us as a whole industry to make some changes around the way that we deliver tourism in New Zealand so that all New Zealanders can be proud of it."
That included freedom camping legislation, the Better Work Action Plan, and destination management plans.
It was vital that tourism benefits communities as well as the economy, she said.