Although Canberrans only account for 1.6 per cent of the national population they are expected to spend 2.1 per cent of the $2.3 billion that will light up cash registers across the country on the busiest retail day of the year.

ARA executive director, Russell Zimmerman, said the Roy Morgan poll indicated post-Christmas sales for the period from December 26 to January 15 would account for almost $16.8 billion nationally.

This is an increase of 4 per cent on 2015/2016 which was a record.

Canberra retail sales for the period are tipped to jump by 2.6 per cent from $288 million to $295 million.

"Pre-Christmas 2015 saw record sales at retail stores and we're expecting to see a very similar growth story play out in the post-Christmas sales," Mr Zimmerman said.

"Boxing Day heralds the opening of the post-Christmas sales period and is traditionally when the biggest savings can be made."

Dean Boerkamp, the assistant manager at Fyshwick's Bing Lee store, said contrary to popular belief working on Boxing Day could actually be fun.

"We're a smaller store and have a close knit team," he said. "Our staff have the choice to work or not and have chosen to do so. While it is a work day there is a different atmosphere [to other days of the year]."

Mr Boerkamp said while there was always the odd customer who was having a bad day most people were in a festive mood.

"We will have 12 to 15 people in the store [serving] and everybody works through lunch," he said.

"We shout lunch and it is usually the fast food group of popular choice. People take 10 minutes, go out the back and then come back and serve. You can be dealing with four or five customers at the same time."

According to the ARA survey Victoria will experience the biggest jump in post-Christmas shopping growth in December and January. Sales are expected to rise by 5.6 per cent to $4.2 billion from just under $4 billion in 2014/2015.

NSW is expected to increase by 3.8 per cent from $5.1 billion to $5.3 billion and the Northern Territory, with the smallest forecast rise of 2.1 per cent, will jump from $172 million to $176 million.

Western Australia is tipped to rise by 3.5 per cent from just under $1.9 billion to about $1.95 billion and South Australia and Queensland are both tipped to rise by 3.3 per cent on 2014/2015.

Mr Boerkamp said one of his funniest experiences during the Boxing Day sales had been when four customers were all after the same item.

"One of them said that as they all wanted it they should be entitled to a group discount," he said.