"Since we started this conversation we've seen between a 20 to 36 per cent drop in plastic-bag usage in our stores – but by the time January 1 rolls around this change will have removed more than 350 million plastic bags from circulation."
The New World in Devonport and the Four Squares in Raglan, Matakana and Martinborough have all gone plastic-bag free already, and other stores are set to follow soon.
From August 29, the New World stores in Howick, Marton and the Pak'nSave in Silverdale will go plastic-free.
Foodstuffs is helping customers prepare for the change by pushing the adoption of reusable bags.
"From October 1, all New World, Pak'nSave and Four Square customers can expect to see an increased focus on reusable bags, with more options available to prepare for the impending ban," Anderson said.
"By the end of March next year we will have given away a reusable bag to pretty much every New Zealander."
The movement against plastic bags has gained momentum in the last year, with Countdown, the Warehouse Group and the Briscoe Group all taking steps to limit the impact of single-use plastic bags.
Countdown released an announcement on 30 July that it would phase out single-use carrier bags at a further 42 stores across the country from 13 August.
This move means that nearly a third of all Countdown supermarkets across the country will have made the change to reusable bags, including all stores in Dunedin, Invercargill, Nelson and Blenheim.
"We are listening to the growing level of concern New Zealanders have around plastic pollution," said Kiri Hannifin, Countdown's general manager of corporate affairs.
"Small changes can make a huge difference, which is why we are moving quickly to deliver on our promise to remove single-use plastic carrier bags, and reduce the use of unnecessary plastic wherever and whenever possible across our business."
In addition to removing plastic bags, Countdown is also taking steps to remove other examples of plastic in its supermarkets.
"So far this year we have removed plastic packaging from bananas, announced we'll be removing single-use plastic straws by 1 October, and committed to moving our in-store bakery products into New Zealand-made rPET sourced from onshore domestic plastic waste," Hannifin said.
There have also been moves across the ditch, but the change hasn't always been accepted by customers.
This week, in response to customer frustration at the inconvenience of not having access to plastic bags, Aussie supermarket company Coles announced a backflip on its policy and said it would offer reusable plastic bags indefinitely because customers were finding it too difficult to remember their reusable bags.