With the Australian Communications and Media Authority's (ACMA) International Mobile Roaming Standard taking effect Friday, Australian customers will have fewer shocks and surprises in their mobile bills.

According to the press release issued by ACMA, the Standard's various components will be implemented in a timely manner. All Australians traveling overseas will receive an SMS alert when they start roaming and get a warning in case significantly higher charges will apply.

Optus, Telstra and Vodafone customers will receive SMS messages informing them of the costs when using roaming services in every country visit.

Medium-scale and smaller telcos are building systems to allow them to send these SMS messages, the report stated. For the meantime, telco customers will be updated regarding roaming prices and an ACMA fact sheet by alternative medium when they seek roaming access, it added.

"The increasing use of smartphones has meant that people using overseas mobile devices without careful planning are at risk of bill shocks and possibly paying tens of thousands of dollars," ACMA Chairman Chris Chapman said.

"These warnings are important because international roaming services are usually priced differently from home services. The overseas charges for receiving calls and casual use of data for activities like maps, social media, email, browsing and uploading photos are often expensive. These further charges vary between mobile plans and among countries," he added.

"Optus, Telstra and Vodafone have all recently announced welcome changes to roaming charges," he noted.

He urged customers to talk to their service providers about the possible options before traveling and tailor the roaming access to suit any particular circumstance.

In June 2013, the International Mobile Roaming Standard created ACMA. It focuses on four key consumer protection measures, which include notification about roaming via SMS to be sent to all consumers; enabling customers to stop international roaming even from overseas locations; SMS notification about pricing information for roaming services; and using management tools, including data usage notifications.