Australia Post is anticipating the biggest delivery day in the nation's history tomorrow, with over two million parcels moving through the network as Christmas Day draws near.

Since October, Australia Post has experienced unprecedented early volumes, already processing over one million parcels every day, as consumers take advantage of pre-Christmas sales and a surge in parcels from China, the UK and the USA.

The record breaking day will see more posties and delivery drivers out on the road tomorrow, supported by an additional 1,500 people assisting across processing facilities.

Australia Post Executive General Manager Parcels, and StarTrack CEO, Bob Black said the increase in numbers is driven by the boom in online shopping, with more people opting to purchase Christmas gifts online than ever before.

"We're finding close to 30 per cent of all online purchases occur in the three months leading up to Christmas, and that's on the back of a 15.9 per cent growth in online shopping this year," Mr Black said.

"Of those purchases, fashion, and toys and games are the most popular purchases, as we see people get more organised for Christmas which is only 14 sleeps away.

"To help our customers receive their online Christmas gifts, we've kept our Post Offices open longer, commenced evening and weekend deliveries, and purchased an additional 10,000 parcel cages – which is around 227 semi-trailers worth of Christmas goodies.

"It's all hands on deck here at Australia Post."

As always, customers are urged to lodge their parcels as soon as possible for delivery before Christmas Day – but Australia Post's range of Express Post items does make it easier for last-minute shopping.

For more information on delivery timetables, please visit auspost.com.au.