Air New Zealand is experiencing the busiest day of the holidays today, with 31,000 booked on flights.
The airline says it is preparing for the 100,000 passengers set to fly around the country for the Christmas holiday period.
More than 30,000 passengers are booked to fly on Christmas Eve, with around 15,000 travelling domestically on Christmas Day.
Air New Zealand chief customer and sales officer Leanne Geraghty says the airline is "excited" to be able to help connect Kiwis with their friends and whānau this Christmas.
The busiest route this Christmas is Auckland to Christchurch, with Nelson being the most popular regional destination.
From now until the end of January, about 600,000 passengers are expected to fly throughout the country with Air New Zealand.
Around half of those customers are flying in or out of Auckland.
Next year will also be off to a busy start with more than 90,000 customers expected to travel over the New Year period between December 31 and January 4.
The check-in process will look a little different than usual for those travelling this summer, with all customers aged 12 or older required to show proof of either full vaccination or of a negative Covid-19 test result taken within 72 hours of travel.
"The process is running pretty smoothly already, and we have had more than 200,000 customers upload their My Vaccine Pass to their Airpoints profile," said Geraghty.
While its domestic operation is busy, changes to border settings announced this week means 120 international services through to the end of February have been cancelled, affecting 27,000 passengers.