WOOLWORTHS will charge a $3.50 "crate to bench" home delivery fee if customers don't want to fork out to buy reusable plastic bags with their online orders from next week.

The nation's biggest supermarket, which is bringing forward the nationwide ban on single-use plastic bags a week ahead of the July 1 deadline, said customers could otherwise opt for a flat $1 fee to have their order packed using heavy-duty bags made from 80 per cent recyclable material.

"We're working to create a greener future for Australia with our customers as we phase out single-use plastic bags both in-store and online from June 20," a Woolworths spokesman said.

"For home delivery orders, customers will be able to choose if they want groceries delivered in reusable plastic bags made of at least 80 per cent recycled material or via our new bag-free, crate-to-bench service.

"With the new crate-to-bench service, orders are packed directly into our delivery crates, and then unpacked on to a customer's bench by a delivery driver when they arrive. The amount for the crate-to-bench option reflects the additional costs of providing this new service."

Coles will not charge a bagless delivery fee. Customers will have the option of purchasing 15-cent reusable bags or having their groceries delivered in a crate.

"Coles Online's new bagless delivery option, which utilises reusable crates, will not incur any additional charge to Coles customers outside of the current delivery fee," said general manager of Coles Online, Karen Donaldson.

"Groceries will be unpacked in the customer's home and crates will return with the delivery driver. This is something our customers have been asking for and we are happy to offer this service at no additional cost."

Recent analysis of Coles' online prices, however, revealed some items were as much as 10 per cent more expensive than in-store. "Many of our customers enjoy the convenience of doing their food shopping online," a Coles spokeswoman said.

"We have worked hard to ensure that customers pay the same price online as in our supermarkets on the majority of products.

"All of the great value catalogue specials available at Coles each week are also available at the same price online, along with more than 3000 Every Day items that are the same low price every day in store and online.

"Some non-advertised specials are only available in a physical store, and our online customers also have access to discounts and promotional offers not available in store.

"Most of our fresh food items such fruit, vegetables, meat, deli, bread, milk and eggs as well as baby-related items such as nappies and baby food are the same regular price online as in store.

"There are some categories where we apply a small price premium and this is to help cover the cost of our convenient service, including the dedicated team members who select our customers' groceries."

From July 1, single-use plastic bags will be banned in Queensland, Victoria and Western Australia, bringing them into line with South Australia - the first state to ban the bag in 2009 - the ACT, Northern Territory and Tasmania.

While NSW is standing firm, the decision by the both Coles and Woolworths to ditch them across their entire store network has resulted in an effective nationwide ban.

Earlier this month, Woolworths group chief executive Brad Banducci said he didn't know if he "would have been quite as brave" in making the decision last July had he known "what a headache" it was to take 3.4 billion plastic bags out of the business.

"One of the things that actually upset me a little bit at the time was there was sort of an innuendo that we will profiteer, because we will be charging for a 15-cent or 99-cent bag," he said.

"Actually [with] the incremental amount of time in store to actually service the customer, certainly it is not a profit driver and we never did it as a profit driver. We did it to do the right thing."