Telstra's mobile customer base now stands at 15.1 million, after the company managed to add 1.3 million new services in the last financial year.

Telstra today revealed that in the 12 months ending June 30, 2013, Telstra's mobile network customer base increased from 13.8 million up to 15.1 million.

In that time, Telstra saw 6 percent growth in its mobile division, with AU$9.2 billion in revenues for the year. The company invested AU$1.2 billion in its mobile network, including expanding its 4G long-term evolution (LTE) out to cover 66 percent of the Australian population.

Telstra also reported that it now has 2.8 million active 4G devices on its network, adding 1.3 million in the last six months alone . A total of 27 percent of Telstra's post-paid customers are now using 4G devices.

Although Telstra has continued to grow its mobile customer base, it is slowing. The company had previously added 1.6 million and 1.5 million new customers in the 2011 and 2012 financial years, respectively.

Customers are generally becoming more satisfied with the telco, according to Telstra CEO David Thodey, with complaints to the Telecommunications Industry Ombudsman down 8 percent year on year. The company has conducted 10 million customer surveys, and has implemented net promoter scoring for customer satisfaction.

Thodey said that each day, he receives an MMS notifying him of the previous day's NPS.

In Telstra's fixed-line division, Telstra reported a decline in PSTN subscriptions down 287,000 to 7.8 million, but this was offset by growth in the company's retail fixed broadband business, with 173,000 new customers in the year. Total revenue in the fixed division for the year was AU$7.5 billion, including AU$399 million of revenue from the federal government as part of Telstra's AU$11 billion agreement for the National Broadband Network (NBN).

This included AU$11 million in retraining, AU$168 million for information campaigns and migration deed, AU$124 million in universal service obligation funding, AU$89 million for infrastructure leasing, and AU$7 million for customers migrating over to the National Broadband Network (NBN).

Telstra's business division reported an income increase of 1.1 percent for the year up to AU$4.7 billion, with double-digit growth in the company's cloud division, up 26.4 percent to AU$278 million in revenue. Telstra's enterprise and government division reported a 1.3 percent growth in revenue to AU$4.3 billion.

Media continued to struggle, with print revenues for the Yellow Pages and White Pages declining 25.6 percent and 11.4 percent, respectively, for a total revenue reduction of AU$193 million to AU$778 million for the year. The company's digital division did see 11.3 percent growth for the year, however, up to AU$415 million.

Total Telstra revenue for the year was AU$25.5 billion, up 1.1 percent year on year, and the company has reported a net profit after tax of AU$3.9 billion, up 12.9 percent year on year.