The Australian Communications Consumer Action Network (ACCAN) says mobile carriers must come clean on exactly how their exorbitant global roaming fees are derived.

The demand follows the introduction of a new international roaming standard introduced by the Federal Government, telecommunications consumer body, Australian Communications and Media Authority (ACMA).

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From September, under ACMA's plans, these carriers will have to provide alerts to travelling customers about the extra costs they might incur should they use their mobile phones on overseas networks.

Telco providers will have to inform their customers of exactly how much they will be charged for making a call, sending a text or going online using their mobile phone when overseas. Providers must also provide usage alerts and information on how to switch off roaming altogether.

ACCAN spokesman, Asher Moses, said the body hopes the new bill will reduce the number of consumers suffering from global roaming bill shock as without transparency on how they are calculated, consumers are prevented from making an informed choice about services.

But while ACCAN welcomes the standard, more needs to be done to end the roaming rip-off, Moses claimed.

"The standard will not solve the underlying problem that global roaming charges are still way too high and do not come close to reflecting the true cost of providing the service. The excuse from providers that they are simply passing on the costs from international carriers is not convincing," he said.

Moses mentioned that ACCAN anticipates the alerts under the new standard to reduce the number of consumers suffering from global roaming bill shock.

On the other hand, ACCAN mentioned, in a statement, that consumers may not be able to properly manage their own usage as the standard defines "current usage data" as anytime within the last 48 hours.

It also has encourages Australia forge bilateral agreements with other nations to help reduce gross over-charging on roaming.

The recent Trans-Tasman roaming agreement between the Australian and New Zealand governments saw both countries commit to passing legislation that would empower their regulators to firstly investigate global roaming pricing and possibly cap roaming pricing between the two countries.