If the container is returned within four weeks, there is no charge. If the container is not returned, Bonson will charge $3 to help replenish the fleet of containers.

However, customers can get a partial refund of $1 if they return the container within six months.

Once returned, Foodstuffs' deli team washes and sterilises the container, readying it for reuse.

Foodstuffs sustainable packaging manager Debra Goulding said the trial was about seeing if returnable packaging could work in supermarkets at scale.

"We know there's often a gap between what people say they'll do and what they actually do. We're going to learn if a returnable system can help customers bridge that gap and whether returnable containers can become the new normal in supermarkets," Goulding said.

Bonson Packaging's general manager Rodney Bennett said he believed RePlay has real potential because it's built on a circular business model.

Key to the trial is learning how many times containers can be reused and understanding the customer return rate, as the system is designed to keep packaging in circulation at high value, rather than being downcycled.

A Foodstuffs spokeswoman confirmed the plan is to have more stores hosting the trial in the coming weeks and months, although she couldn't provide details as to when or where.

Helping fund the RePlay initiative is the Government's now-closed Plastics Innovation Fund, which was funded by the waste levy.

The Ministry for the Environment has allocated $329,725 towards the project, with Environment Minister Penny Simmonds confirming that Bonson has claimed about half of the available funds.

Simmonds said the Government recognised the important role industry can play in reducing the release of plastic into the environment.

"The Government is committed to practical, evidence-based solutions and we welcome industry-led trials that allow businesses to test, refine and demonstrate what works in practice. These kinds of initiatives help ensure schemes are effective, manageable, and scalable before wider adoption," she said.

"The ministry's contribution to this initiative is modest and designed to support industry leadership. This is not a large, taxpayer-funded programme, but rather targeted support to enable collaboration, innovation and testing of approaches that can inform future policy and regulation."

As to how the initiative's funding aligns with the Government's scrapping of the 2025 deadline for the third tranche of plastic phase-outs, Simmonds said the Government's commitment to reducing plastic waste remained firm.

"We are progressing product stewardship schemes and legislative reforms to modernise how we manage waste and ensure cost-of-living impacts are minimised."

She said plastic waste was a global issue and that New Zealand continues to participate in international efforts to develop a global treaty to end plastic pollution.

Govt-backed Foodstuffs trial aims to cut single-use plastic waste