Two of the country’s biggest telcos, Telstra and Optus, have confirmed that they will push back the deadline to shut down their 3G mobile networks to October.

Telstra and Optus had planned to close those networks on August 31 and September 1, respectively. However, both will now do so on October 28.

Optus’s interim CEO, Michael Venter, said “the majority” of its customers who would be impacted by this were “now on compatible devices”.

“We are 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,” said Venter.

Telstra’s CEO, Vicki Brady, reiterated the efforts made to communicate to customers about the eventual 3G shutdown “for almost five years”.

“This has included multiple letters, bill messages, SMS, public awareness campaigns, advertising – even doorknocking and sending free phones to people in vulnerable circumstances,” said Brady. “And our support for customers won’t end the day the network closes.”

Some of the criticism directed towards the planned 3G shutdown was the number of older 3G phones and early 4G phones which would not be able to make emergency calls over the 4G network.

At the start of this year, 740,000 devices were affected, but that number has drastically reduced to 77,000 at the start of this month.

Communications Minister Michelle Rowland welcomed Telstra and Optus’ decision to delay the shutdown of their 3G network, while urging those who had not yet switched devices, to do so quickly. “While I am pleased that customers and businesses now have additional time to prepare for the 3G switchover, I want to encourage all Australians to take action and check if their device could be impacted,” said Rowland.

Users who are unsure if their device will be affected can text “3” to 3498 and they will receive a message notifying them of whether their device will be impacted by the shutdown.

Beyond mobile phones, some have drawn attention to equipment such as Eftpos machines, ATMs, CCTV and medical alert devices that connect via 3G.

Telstra told a parliamentary inquiry last month that it has 399,000 internet-of-things devices (such as water meters, electricity meters and more) that are not 4G-capable, as well as 63,000 early-version smartwatches and 45,000 wireless broadband devices or tablets. Optus says it has about 100,000 devices predominantly used by businesses, including payment terminals, monitoring and telemetry devices.