Coles has announced due to "unprecedented demand" for groceries and household staples it will temporarily suspend online delivery orders "to dedicate vans in our network to delivering groceries to those in genuine need, especially the most vulnerable and those isolated".
Household essentials such as toilet paper, rice, pasta, and hand sanitiser have been flying off the shelves amid COVID-19 panic buying.
Coles has also suspended its UberEats delivery service and will temporarily no longer accept click-and-collect orders.
The grocery giant, however, reassured that it is not running out of food.
"There is enough for everyone if people shop as they would normally shop," it said.
Temporary shortages have also seen Woolworths "temporarily pause" its click-and-collect services nationally.
"We have temporarily paused our online 'Pick up' and 'Delivery Now' (our on-demand, in under 2-hour delivery service) services due to temporary shortages on a number of items and to allow our teams to focus on serving customers in-store," the company said on Sunday afternoon.
"Refunds on any existing orders are currently being processed.
"We apologise for any inconvenience caused and thank you for your patience during this time."
Woolworths' online delivery services out of its Victorian supermarkets have also been temporarily suspended. It noted, however, that online deliveries in selected metro areas in the state would be serviced from its West Footscray fulfilment centre.
It is unclear when exactly Woolworths will resume its online services as normal, but the grocery giant stated it will look to make it happen "as soon as possible".
On Monday afternoon, Coles also announced it would offer allocated shopping time for the elderly and the disadvantaged, as part of what it has dubbed as "community hour". The company said it will temporarily change its trading hours to open 7 am to 8 pm on weekdays, with the exception of Western Australia and parts of Queensland where the hours will be 8 am to 9 pm.
The first hour of trade, Coles said, will open exclusively to customers who hold a government-issued pensioner concession card, Commonwealth seniors health card, companion card, and health care card.
Supermarkets that open at 7 am will also close no later than 8 pm to enable time to replenish the shelves for customers the next day, Coles said.
The retailer added it will review the arrangements "as necessary".
Woolworths is also offering the same for the elderly and people with disability, which will be in place until March 20. It will allow them to shop from 7 am to 8 am, with proof of relevant government issued concession card.
Updated 16 March 2020 5.06pm (AEDT): Coles has announced it will temporarily suspend online and click-and-collect deliveries, and it will make changes to its trading hours.