UPDATED 11.59am: The Boxing Day shopping frenzy is well and truly underway in Auckland, with people cramming into the malls.

There are long lines outside some shops which don't have space for any more shoppers.

MORE: Roads jammed amid Boxing Day mayhem 

Kieran Bell has just given up and left St Luke's Mall - he said he can't bear the sheer number of people.

"It's not even controlled chaos, it's just chaos."

"There's people lining up across where you'd walk, so people can't get through. Every store is just filled with people, so after about 15 minutes I had to leave, it was pretty hectic in there."

Darrin McLay has been at the Harvey Norman store at Wairau Park.

He said 400 people were crammed inside the store, minutes after the doors opened.

"The store was meant to open at 8 o'clock and 8 minutes past 8 the Playstations were gone - all of them on the special deals they had."

Mr McLay said there were about 400 people crammed inside the store, minutes after the doors opened.

After a strong run-up to Christmas, this year's Boxing Day frenzy is expected to top last year.

Westfield said Boxing Day brings a lot of people out with gift cards and vouchers.

Retailers should be happy with the Christmas season so far. EFTPOS company Paymark processed almost $148 million worth of sales between midnight and 1pm on Christmas Eve.

The company said the last two days before the day itself point to a very strong Christmas period.

Meanwhile, it seems the day after you received it is definitely not too soon to be selling that gift you didn't really want.

Trade Me says more than 4000 items have already been uploaded with the words 'unwanted gift’ in the description.