Some carriers have as much as halved data allowances on popular phone plans, while a recent slew of cuts has seen up to 1.5 gigabytes slashed from others.
Industry analysts say slugging smartphone users more for internet downloads has become the easiest way to make money, now our eyes are more often trained on the screen than our ears are pressed to the phone for calls.
Australia's love affair with mobile internet downloads was highlighted earlier this week with the Bureau of Statistics revealing phone data use had almost doubled in the past year, up 97 per cent by June.
The country's 19.6 million internet-savvy phone users downloaded 19.6 terabytes of data to their handsets between April and June, blowing away the 9.9 terabytes from the same period in 2012.
ABS spokesperson Lesley Martin said the "explosive growth" had occurred even though mobile phone subscribers only grew by 21 per cent during that time.
Despite the skyrocketing demand, Australia's phone carriers are reducing the data in their deals.
Optus and its offshoot Virgin Mobile recently announced a new range of plans with download allowances as little as half of what they were a year ago.
Vodafone also halved the data available on its $50 plan, and Telstra cut 500MB from several of its high-range phone plans.
Telsyte managing director Foad Fadaghi said the carriers were cutting data allowances because that's where the money was.
While carriers once profited from voice calls and SMS messages, he said, consumers were now more interested in connecting to the internet, streaming video and songs, and using social networks on their smartphones.
"We noticed recently that revenues from data services and messaging have exceeded that of voice revenues for the first time," Mr Fadaghi said.
"The popularity of data packs represents the greatest growth opportunities for telcos and they're being a little bit more discerning with what they include in plans as a result."
Cameron Craig, director of phone plan comparison site WhistleOut, said there was no doubt smartphone data allowances were shrinking in Australia, but argued that carriers only offered large data bundles in the past because they didn't expect them to be used.
While even modestly priced plans had offered as much as 2GB of mobile downloads, he said, it was often unfeasible to use that much data with the handsets and network speeds on offer.
"If you're looking at an iPhone 3G, the browser was slow to load anything, the processor was slow to render video. It was a struggle to use the data back then," he said.
"With the speed of handsets increasing, and the network speeds increasing dramatically, the use of data has gone up and up."
Mr Craig warned that phone carriers were also being sneaky about how they billed for data, and consumers should ensure they were billed by the kilobyte and not by larger, megabyte increments.
"It's the same as talking for one second on a phone call and being billed for one minute," he said.
"If you do lots of small checks or small posts back and forth to the internet from your phone, looking at Twitter or checking your email, each hit can be rounded up to a megabyte."
Mr Craig said Australian phone users should shop around and, if they're on a good plan, consider buying a new smartphone outright to stay on it.
news.com.au 10 Oct 2013