Australia's mobile networks run on three underlying infrastructure owners — Telstra, Optus and TPG (which also supplies the Vodafone brand) — with every retail plan, including budget virtual-network brands, ultimately using one of these three. From 30 June 2026, all three are required to publish coverage maps using the same standardised four-category system (good, moderate, basic, no coverage) under new rules from the Australian Communications and Media Authority, replacing each carrier's own previous mapping method. Under the new standard, Telstra's mapped geographic footprint is the largest at just over 2.14 million square kilometres — still meaningfully bigger than Optus or TPG/Vodafone's roughly 1.2 million square kilometres each — though the new methodology reduced Telstra's previously advertised area by close to a million square kilometres, a reminder that "coverage area" numbers depend heavily on the measurement standard used.

In population terms the three are closer together: Telstra reports around 99.7% population coverage, with Optus and TPG/Vodafone (helped by a 2025 network-sharing agreement between Optus and TPG that roughly doubled Vodafone's effective footprint) both around 98.5%. The practical distinction is geographic rather than population-based — Sydney, Melbourne, Brisbane, Perth and Adelaide are well covered by any of the three, but Australia's vast interior, remote coastal stretches and outback highways see real dead zones regardless of network, and Telstra's deeper rural infrastructure is the most consistently recommended option specifically for travel well outside the main population centres.

Australia does require identity verification before a prepaid mobile service is activated — name, date of birth and address, checked against government identity documents — a requirement in place since 2017 and unrelated to the separate "100-point" identity check used for banking and other transactions. This applies to locally issued prepaid SIMs; it is a different process from activating a roaming data eSIM, which does not issue a new Australian-registered line.

The usual sequence still applies: install the eSIM profile over Wi-Fi before the flight, keep the home SIM active for calls and passcodes, and switch on the data eSIM once landed — and plan for possible dead zones on any outback or remote-coastal leg of the trip, regardless of which network is in use.

Buying an Australian prepaid SIM requires identity verification — name, date of birth and address checked against ID — under rules in place since 2017, separate from an eSIM's activation process. The more consequential planning point for Australia is geography rather than registration: even the widest network's coverage area leaves large parts of the outback and remote coastline uncovered, so an outback or remote-coastal leg of a trip should not assume signal will be available throughout, on any SIM.