Wellington has become the country's most expensive city to rent in as rents in the capital soared by 5.8 percent in the past year.
Trade Me's latest figures put median weekly rent there at a record high of $565 a week, $15 more than in Auckland.
Trade Me's head of rentals Aaron Clancy said listings were down by 7 percent last month compared with December 2017.
Meanwhile the number of inquiries went up by 15 percent, leading to big queues at open homes.
Mr Clancy said with growing demand for rental properties in the Wellington region, and tight supply, there would be more record-breaking rents to come.
"As house prices in the capital continue to rise, more Kiwis are having to stay in their rentals longer to save for a deposit and this is driving demand."
He said high demand for housing usually hit the region around January and February, but this year it appeared many tried to beat the rush and secure a property before 2019 had even begun.
"This supply vs demand equation is pushing rents up really quickly and there isn't any relief in sight for now. We're already seeing huge demand and interest in rental properties across the first few weeks of 2019."
Mr Clancy said rents in Hutt Valley and Porirua were cheaper than in the central city but demand was still high.
"A property in Wainuiomata, typically a very quiet suburb for rents had 95 enquiries in its first two days on Trade Me."
The most popular rental in December was a two-bedroom house in Newtown, which had 137 inquiries in the first two days.
Rents in Auckland were unchanged from the year before at $550 per week.
The national median weekly rent remained stable for the fifth month in a row at $480, up 4.3 per cent on the year before.
Bay of Plenty (up 9.1 per cent to $480), Manawatu/Whanganui (up 16.7 per cent to $350), Marlborough (up 6.5 per cent to $450) and Southland (up 10.3 per cent to $295) all reached new records in December as the rental market in the provinces heated up.
The Nelson-Tasman region was down 2.4 percent on December 2017 and was the only region which didn't have an increase in December.