TPG Telecom/Vodafone have already turned off its 3G network, in a bid to boost the speed, capability and reliability of their 4G and 5G system

Federal Communications Minister Michelle Rowland has urged all Australians to check and, if needed, upgrade their tech.

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.

With AAP.

Image: Getty