By June 30, 36 per cent of Australian adults had scrapped their landline, up from 22 per cent five years ago, the Australian Communications and Media Authority's latest communications report found.

If the move away from the landline continues at the same pace, the majority of Australians would be mobile-only within the next five years.

"The trend away from landline phones for voice communication has continued for a number of years and has not slowed in recent years," ACMA senior research analyst Kylie Trengove said.

Providers had been offering home telephone handsets when customers connected to cable and fibre-internet services, including the national broadband network (NBN), which could slow their decline.

"However, our research shows that consumer reliance on mobile phones is continuing to strengthen, with volume of data downloaded over mobile phones handsets by 45 per cent," Ms Trengove said.

"Consumers are also increasingly reliant on their mobile phone for communication in a number of ways including making voice calls and sending SMS, along with use of communications apps for messaging or to make voice or video calls."

Now, eight in 10 Australian adults own a smartphone - up from 64 per cent five years ago.

Mobile has also become the most-used device to access the internet, for both the proportion and frequency of use, with 84 per cent of people using their mobile devices to access the internet daily.

This outstripped both laptops and desktop computers.

Phone operators recorded 4G coverage for 96 to 99 per cent of the Australian population, with 33.64 million mobile services in operation.

And while questions have been raised about whether a 5G future could make the NBN obsolete, mobile-only access to the internet is still yet to get a huge amount of traction.

"Despite the increase in internet access over mobile phones, there has not been a corresponding decline in internet access over fixed networks and there is not a clear trend towards mobile-only for internet at this stage," Ms Trengove said.

Six per cent of adults used just a smartphone to connect to the internet with no other option at home.

The increase in smartphone and internet use also coincided with a significant increase in data usage - 3.1 million terabytes were downloaded in the June 2017 quarter. This was up 43 per cent year on year.

Communications Alliance chief executive John Stanton said the data showed the "growing dominance of mobile phones to access the internet".

"Apart from the convenience of mobile online access, the figures also reflect the much more generous mobile data allowances available in the market - largely freeing consumers from past concerns about the cost of mobile data and the risk of hitting monthly data limits," Mr Stanton said.