The mail service delivered 52 million parcels in the December peak as more than 5.6 million households shopped online.

The number of online purchases rose 1.5 per cent year-on-year from 2020, and was 37.5 per cent more than in 2019.

As consumers emerged from a year with widespread COVID-19 restrictions and lockdowns, more than 1.8 million households shopped online at least four times in December.

Parcel volumes in October and November also exceeded previous years, but the busiest day of the season was December 13, when 556 tonnes of parcels were moved.

There were 17 days when more than two million parcels were delivered and Australia Post used 25 dedicated freight planes to carry more than 8.7 million kilograms of parcels - up 13 per cent on 2020.

Western Australia saw the biggest year-on-year purchase growth, with an uptick of 8.9 per cent, followed by NSW with 5.6 per cent and the Northern Territory with 5.2 per cent.

People increasingly moved online to manage their parcels, with the Australia Post app reporting 83 million visits and five million parcel arrival alerts.

Australia Post spent months preparing for the surge in demand over the festive period and had delivered for Australians, despite the challenges presented by the pandemic, Group CEO and Managing Director Paul Graham said.

"That we have seen another 52 million parcels delivered at Christmas demonstrates the dedication of the people in our post offices, our licensed post office partners, and everyone working across our processing, delivery, customer teams including more than 5000 new team members who helped make it possible," he said in a statement on Monday.

Australian Associated Press