The communications regulator and consumer groups have sounded warnings on 4G smartphone bill shocks after studies showed users of newer phones could double their data usage compared with 3G.

The new iPhone 5 and the 4G version of the Samsung Galaxy S III are expected to drive an uptake of 4G, which offers download speeds that are up to four times faster than 3G. The extra speed will make it much easier to stream music and video, activities that burn through mobile data allowance much quicker.

The Australian Communications and Media Authority is so worried about the risk of bill shock for 4G users that it sounded a warning this week. The type of 4G network adopted in Australia is known as LTE, or Long-Term Evolution. Joint research by Canada's Mobidia Technology and Informa Telecoms and Media revealed LTE networks and devices are stimulating increased data usage, by up to 50 per cent in some cases.

A separate 4G study by mobile intelligence firm Validas found the addition of LTE in a phone could double consumers' use.

In its warning, the Australian authority said: ''Users could use more data than they're used to and may experience bill shock as a result.''

Changes in the new telecommunications industry code will mean that from October 27 telcos will have to offer standard pricing information to make it easier to compare offers from carriers.

But requirements for more detailed critical information summaries on plans won't come into effect until March 1.

The Australian Communications Consumer Action Network said that in light of this, people buying the iPhone 5 needed to be careful before signing a two-year contract.

''What we're seeing with the iPhone 5 plans currently on offer is low data inclusions at the lower end of the market, which is happening across all providers as data becomes more expensive,'' consumer network spokeswoman Elise Davidson said.

''It's tempting for consumers to sign up for a lower monthly price but be warned, if you go over your included allowance, excess data charges are notoriously punitive.''

Ms Davidson said disputes between customers and their providers about excess data charges had almost tripled in the past year as customers received unexpected bills running into the thousands. Asher Moses