At Stockland Shellharbour, Harris Scarfe regional manager NSW/ACT Andrew Cornford said the customer numbers had been promising.

"For retail it has been a pretty challenging 12 months right across the board, so to have a buoyant sales period now, it's important," he said.

"Looking at the foot traffic in here today I'm very confident we will have great Boxing Day sales."

In a more generous campaign than last year, the department store singled out individual items for deeper, targeted discounts - often 50 or 60 per cent - on top of its "global offers", where the entire line of cutlery, for instance, was reduced by 40 per cent.

Beachwear retailer Surf Dive 'n' Ski also made more dramatic price cuts to combat trouble on two fronts - the year-long retail slump and the cold summer, which had driven down sales of beachwear.

"It's a block sale this year," the Shellharbour store's third-in-charge, Chelsea Riches, said.

"Usually it's individual items that aren't selling well but we have targeted more things that wouldn't usually be on sale."

At Hairhouse Warehouse, owner Lube Markovski was expecting to sell out of 200 heavily discounted gift packs.

He said pre-Christmas sales had also been steady.

"Boxing Day sales are critical for any retailer but we've actually had a really good Christmas," he said.

"We've had a whole week of people coming in."

A survey by the Australian National Retailers Association found about 54 per cent of Australians planned to attend post-Christmas sales.

The association's CEO Margy Osmond said retailers anticipated $1.7 billion in sales nationally.

"Retailers will be pleased the start of Boxing Day has proved so popular and hope to see more of the same over the next few days as stores reopen after the holidays," she said.

"We are hoping the post-Christmas boom lifts December sales to the levels we wished for when the season kicked off."

Shopping centres in Shellharbour and Kiama shopping are permitted to trade on Boxing Day because the State Government classifies them as "holiday destinations".

Centres elsewhere in the Illawarra are classified differently and did not trade yesterday, however a group of five Wollongong stakeholders are campaigning to a panel that is reviewing Boxing Day trading laws.

Wollongong Central will open today (from 9am to 6pm), as will Westfield Warrawong (8am to 6pm) and Stockland Corrimal (10am to 4pm) and Westfield Figtree (8am to 6pm).