With stock levels dwindling and some 'Boxing Day” sales launching on Christmas Eve, the pickings could be slim come December 26.

In an email to customers on Thursday, The Warehouse Group announced its online sales would begin early.

Boxing Day deals would be available through the Noel Leeming website from 7:30pm on Christmas Eve, while The Warehouse would launch its sale at 8pm.

Rebel Sport and Harvey Norman were also among those launching their sales early.

But as the global supply chain strains under the pressure of Covid-19 and many retailers face dwindling stocks, actually bagging a bargain could prove difficult.

At Kmart Riccarton, Christchurch, toys were few and far between as Christmas approached and shoppers reported similar scenes at other Kmart stores nationwide.

A spokeswoman for the retailer confirmed it was struggling to stock the shelves in certain categories as port congestion affected its ability to get products into stores.

The Warehouse had also felt the effects of shipping delays but had taken extra steps to keep stock levels up during the festive period, a spokeswoman said.

Like Kmart, some categories could be impacted but more stock was on the way.

Adding to the headache for those tasked with keeping shelves stocked, Kiwis have been shopping – quite literally – like never before.

Traditionally the busiest shopping day of the year, Christmas Eve 2020 was no exception, according to Paymark.

By 2pm Thursday, shoppers had spent more than $166 million through the electronic card network, setting a record for transactions per second in the process.

At 12:30pm, transactions peaked at 204 per second, 16 per second higher than the previous record and more than three times the daily average of about 60 per second.

-Stuff/Esther Taunton.