iiNet Limited is Australia's second-largest internet service provider with more than 1.3 million customers as of 15 August 2011. It was acquired by TPG Telecom in September 2015 for $1.56 billion, but retained its retail brand name in the market. Its subsidiaries include Internode, Westnet, AAPT Limited, Adam Internet, TransACT and Netspace. Their focus is primarily on ADSL-based Internet access, using their own ADSL2+ infrastructure, reselling Telstra ADSL services and more recently in reselling the NBN. iiNet also provides optical-fibre, dial-up, and voice services.
iiNet has in its growth acquired or merged with many smaller ISPs building a substantial customer base in Western Australia, and then, by acquiring ihug and OzEmail, expanded significantly into the eastern states.