Remembering re-usable bags should be one of every shopper's New Year's resolutions - single-use plastic bags will be gone from all major supermarkets from Tuesday.
New World, Pak'nSave and Four Square have joined Countdown and will ban single-use shopping bags from January 1, 2019.
Countdown made the move in October 2018 after the Government confirmed it would ban single-use plastic bags by mid-2019.
The ban by Progressive, which owns Countdown, and Foodstuffs, which owns Pak'nSave, FourSquare and New World, will remove a staggering 700 million plastic bags from circulation in New Zealand next year alone.
The Government ban will also include thicker bags of up to 70 microns, and compostable bags, because of a lack of recycling facilities for them.
Thin barrier bags will still be used to separate food like fish and chicken from other items.
Associate Environment Minister Eugenie Sage has confirmed the bag ban will apply to all retailers, including those in malls and chain stores.
The ban was flagged by Sage and Prime Minister Jacinda Ardern back in August and included five weeks of public consultation.
The majority of 9349 submissions, or 92 per cent, supported a mandatory phase-out of single-use plastic bags.
Sage said New Zealanders were aware of the impact on sea life caused by the bags.
"It is because of the significant problem we have of plastic bags getting into the marine environment and examples all around the world of whales, seals, seabirds, turtles being suffocated and killed by marine pollution," she said.
Countdown supermarket said the transition to reusable fabric bags had been smooth with an increasing number of customers remembering to bring their bags to the check-out.
The companies have also pledged to reduce another plastic packaging.
New World has switched from polystyrene meat trays to recyclable trays and is trialling a "bring your own container" in the meat and seafood department in some stores.
The stores included Howick, Levin, Hastings and Rotouna.
"We're looking at extending the trial to other parts of the store, but customer safety is a top priority and our food safety team is working through how we can roll out the initiative to other departments," a spokesperson said.
Countdown said it had removed 70 tonnes of unnecessary packaging from its produce section in the past year alone - including plastic packaging from bananas.
"This alone removed 15.8 tonnes of plastic. We also no longer sell packs of single-use plastic straws," a spokeswoman said.
In June, 12 international and several local businesses gathered with Environment Ministers and made a joint declaration committing to use 100 per cent reusable, recyclable or compostable packaging in their New Zealand operations by 2025 or earlier.
The businesses include multinationals Amcor, Danone, L'Oréal, Mars, PepsiCo, The Coca-Cola Company, Unilever and Nestlé.
The New Zealand-based businesses that signed the Declaration include Foodstuffs, Countdown, SuperValue, Fresh Choice, New World, Pak'n Save, FourSquare, New Zealand Post and Frucor Suntory.
Foodstuffs also confirmed it donated tonnes of food that was too good to throw out but not good enough to sell.
The equivalent of 5.6 million meals was donated to local communities in the last 12 months.
New World's tips to remember your reusable bag
• Hang your bags on or near the front door handle, so you can grab them on the way out the door.
• Put a reminder note in your car. Hang it from the rear-view mirror or stick it to the dashboard.
• Keep a small foldable reusable bag inside your handbag, backpack, or satchel so you'll always have one on hand.
• Write 'Bring Bags' on the top of your shopping list.
• Use the power of nagging and designate a chief "bag reminder-er", such as your kids, flatmate, friend or partner.
• Get crafty and make your own bags or support Boomerang Bags which makes bags to borrow and return.