Australia-based Telstra and Optus again pushed back the date for closing down 3G services, following a senate inquiry raising concerns, with the shutoff now scheduled for 28 October.

In a joint statement the pair explained they will conduct a public safety awareness campaign about the impending move, noting it is critical customers check devices are compatible with 4G or 5G to ensure they are still able to call emergency services.

Users of connected devices such as medical monitors, IoT sensors and some electronic payment terminals also need to check whether they use 3G networks by contacting the manufacturer or supplier, the statement added.

The two operators stated they had “listened to feedback from stakeholders” and made significant investments and upgrades to prepare for the transition away from 3G.

Telstra and Optus had been scheduled to turn the service off in the coming weeks, having already delayed their initial timelines.

They insist the move is necessary to free up spectrum to improve 4G and 5G services.

Optus interim CEO Michael Venter said it is joining with Telstra to launch a final public awareness campaign to “really drive home the safety message and get the final groups of customers to act”.

Telstra CEO Vicki Brady added: “our support for customers won’t end the day the network closes,” noting it has been communicating to customers about the need to prepare and make the move for almost five years.

Data from GSMA Intelligence showed Telstra ended June with 70,900 3G users, while Optus had about 10,600.