[4] Australia's telecommunications services were originally controlled by the Postmaster-General's Department (PMG),[5] formed in 1901 as a result of Australian Federation.

Telstra has faced competition since the early 1990s from Optus (Australia's second largest communication company) and a number of smaller providers.

[21] Telstra agreed to "disconnect"[22] its Internet customers from the copper and hybrid fibre-coaxial networks in areas where FTTP has been installed, and agreed to lease dark fibre, exchange space and ducts to NBN Co. As part of the agreement, Telstra would not be able to market their mobile network as an alternative to the NBN for a number of years.

[27] Early in 2010, Telstra announced the creation of a $1 billion "fighting fund" to be used in a concerted effort to win back market share in key product categories.

[52] At a results announcement, CEO David Thodey remarked that "the group's new online strategy was delivering" in the context of a 28% reduction of inbound service calls.

[53] Telstra estimated that its digital program will provide productivity benefits of $100 million in the 2013 financial year from lower printing costs, decreasing commissions to third parties, and reduced dependence on call centre staff.

[54] In October 2012, Telstra's CEO David Thodey stated, "The rise of online and social media had 'fundamentally changed the way' which the company communicated with its customers".

[74] 109 of Telstra's stores are owned and operated by Vita Group, a publicly listed company with a market capitalisation of approximately $600m (June 2016).

[101] Sensis was said to have once been "one of Telstra's most lucrative businesses" and reportedly "has been under pressure in recent years amid competition from more agile digital alternatives such as Google".

Penn indicated new focus on growth in the core business with a pulling back from international markets,[120] including the discontinuation of a joint venture to build a mobile phone network in the Philippines.

[121] On 14 March 2016, Telstra ended their talks between the company and the Philippine-based conglomerate San Miguel Corporation for a planned joint telecommunications venture in the Philippines due to several factors.

[125] In December of that year, Telstra announced the appointment of Robyn Denholm as its new COO, following the departure of Kate McKenzie who left after the network outages.

[130] In August 2017, Telstra announced that it would cut its dividend in response to the financial implications of the NBN and to fund its network investments, leading to a drop in share price by over 10% in a single day to reach a 5-year low.

[132] Composed of four pillars, the strategy was designed to remove $1 billion of operating costs from the business, simplifying its overall structure and leading to six key outcomes: improve customer experiences, simplify its products and operating model, extend network superiority and 5G leadership, achieve global high performance in employee engagement, reduce net productivity costs, and attain a return on capital investment post the NBN rollout.

[133] Created on 1 July 2018, Telstra InfraCo[134] would serve as the infrastructure business, owning an estimated $11 billion AUD in assets made up of data centres, non-mobiles related domestic fibre, copper, HFC, subsea cables, exchanges, poles, ducts, and pipes.

Ultimately the T22 strategy proved to be very successful with a significant improvement in customer metrics, employee engagement, a return to profitable growth supported by a $2.7 bn reduction in annualised costs.

Communication Workers Union national assistant secretary James Perkins criticised the lack of staff warning prior to the announcement.

[citation needed] 1800 MHz capacity channels were added to the network in the late 1990s as well as GPRS packet data transmission capabilities.

The first cellular system in Australia offering portable hand-held phones was launched by Telstra in 1987 using the AMPS analogue standard on the 800 MHz band.

[158] Telstra Wholesale[159] provides products such as Data, Mobile, Voice, and other Facilities (including Co-location and Duct Access)[160] to other companies and organisations for re-sale.

On 6 February 2008, Telstra announced that it would activate high-speed ADSL2+ broadband in a further 900 telephone exchanges serving 2.4 million consumers across every state and territory in Australia.

[180] Telstra's Hybrid Fibre Coax (HFC) (commonly referred to as "cable") network is one of the delivery systems used by the Australian Subscription Television provider Foxtel.

[182] MOG, a subscription online music service and blog network, announced a partnership with Telstra offer their product in Australia – the first region outside of the United States to have access.

GameCreate was a service offered free of charge where users may book a server for a specific game for a 2-hour period of time.

September 2015: Telstra, in collaboration with NETGEAR, Ericsson and Qualcomm Technologies announce that it is bringing the world's first 4G LTE Advanced 600 Mbit/s Category 11 device to customers.

[199] September 2016: Telstra conducts the first live 5G trial in Australia with Ericsson, demonstrating 5G capabilities in a real world environment, including speed and beam steering tests.

[needs update] [223] On 1 January 2015, Telstra launched, what it calls "4GX": a 700 MHz based component of its mobile network claiming speeds of up to 75 Mbit/s with compatible devices.

[224] 4GX has been expanded up to a 5 x Carrier Aggregation LTE Advanced Pro network, with up to two gigabits of capacity in selected locations using 700, 1800, 2100 and 2600 MHz frequencies.

[244] On 20 March 2019, Telstra denied access to millions of Australians to the websites 4chan, 8chan, Zero Hedge, and Liveleak as a reaction to the Christchurch mosque shootings.

A Hillston farmer voiced fears that losing 3G connectivity could disrupt communication with her family in other rural places, posing potential risks to their safety and well-being.