Telstra is due to switch off on August 31, Optus will close from September, while TPG/Vodafone ceased operation of the ageing network in January.
The closures and potential risks are the subject of a Senate inquiry, which is holding public hearings in Cooma, southern NSW, and Canberra on Tuesday and Wednesday.
Telstra plans to switch off 3G on August 31 and Optus will follow a month later. (Joel Carrett/AAP PHOTOS)
Connectivity barriers in rural areas are long-standing and the 3G shutdown must not exacerbate an already "tumultuous" system, the National Farmers' Federation said in its submission to the inquiry.
The farming peak body said mobile coverage should be equivalent or improved after the closure and telcos needed a back-up plan if rural people are cut off.
"Australian farmers and communities are placing significant trust in providers to ensure that the transition away from 3G technology is as seamless as possible," the federation said.
"Providers must recognise their actions during this transition period will significantly impact their relationship with these communities."
Telstra and Optus have committed to equivalent coverage and say the closure will help expand 4G and 5G.
Many rural Australians are worried about being cut off from health and emergency services, or having their personal medical alarms fail after the shutdown.
The National Rural Health Alliance, which represents 52 organisations, said older people and those living with disabilities felt particularly vulnerable.
Telstra has acknowledged the challenge of reaching people with medical alarm devices using 3G SIM cards, as they cannot be tracked like phones.
The telco has been working with the alarm providers, including the aged care sector, to make sure the devices are upgraded in time.
The NSW government's Telco Authority said communication black-outs during the 2019 bushfires and last year's Optus outage showed how much regions rely on connectivity.
"Without coverage, they become isolated communities," its submission said.
Last week, the federal government said 102,000 active mobile phones aren't compatible with 4G, although that's a sharp decrease from more than 740,000 in March.
The telcos have a service for customers to check the status of their device by texting "3" to the number 3498.
While the Senate committee isn't due to report until November it has been urged to hand down its initial recommendations before the 3G shutdown.
4°C