In a bid to boost the speed, capability and reliability of their 4G and 5G system, TPG Telecom/Vodafone have turned off 3G.
Telstra and Optus will follow suit on Monday.
Federal Communications Minister Michelle Rowland has urged all Australians to check and, if needed, upgrade their tech.
Michelle Rowland says people with devices still using 3G need to take immediate action. (Mick Tsikas/AAP PHOTOS)
Telcos have been preparing for the closures since 2019, but the official shutdown has been delayed twice due to concerns over a particular type of phone - often purchased overseas or second hand - that cannot connect to triple zero on newer networks.
These handsets use 4G for regular calls and texts, but 3G for the emergency line, with fears many would not experience issues until they attempted to call the emergency line after the network's closure.
"If you or someone you know has one of these 3G devices, please take action now and contact your service provider," Ms Rowland said.
"My department will continue to work with the telcos during the switchover process to ensure in occurs in a safe and effectively managed manner."
To address the 60,000 affected phones in circulation, a new federal law will also come into effect on Monday, forcing telcos to disconnect voice and data services on these devices.
Australians can find out if their phones are affected by texting "3" to the number 3498.
Time is running out! The 3G network closes on Monday.— AusGov Media & Tech (@AusGovMediaTech) If you or someone you know use a 3G or 4G mobile, text '3' to '3498' to find out if it will be impacted. Other devices such as personal medical alarms and smart watches may also be impacted. Visit https://t.co/KkttcCXoSW pic.twitter.com/Iu6UyJpyiuOctober 24, 2024
The shutdown will also impact devices such as smart watches and medical alarms.
For five years, mobile service providers have made efforts to advise affected customers and urged them to upgrade any technology reliant on 3G.
All telcos have offered handset replacement options, with some providing free devices for vulnerable members of the community.
Tasmania will be the first state to have its 3G network switched off and the other parts of the nation will be turned off by November 4.
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