Malaysians performing the haj are advised to be well-informed on international roaming service with their mobile phones to avoid receiving a huge telecommunications (telco) bill when they return home.

The Communications and Multimedia Consumer Forum of Malaysia (CFM) said they needed to understand how international voice and data roaming works and what the charges were for these services under their current mobile plan.

"This is very important as consumers are responsible for all charges incurred while overseas as these services involve not only their service provider in Malaysia but also the roaming partner in the country they are visiting," CFM said in a statement today.

It added that consumers might want to explore other alternatives to stay connected with their family and friends while overseas.

One of the tips on international roaming shared by CFM is that if people just want to receive calls and SMS while overseas, they can choose to turn off data roaming completely.

Consumers should also deactivate the 'Automatic Connection to Networks' setting and ensure they are always connected to the service provider's roaming partner to enjoy preferential rates.

"Should you wish to stay connected on Wifi only, you can choose to switch your mobile phone to 'Airplane' or 'Flight' mode and make use of public WiFi hotspots available," CFM said.

It said a cheaper option might be to get a local Saudi SIM card and choosing the best package that suits the intended usage for the duration of the stay.

"It's always useful to bring a spare cheap feature phone just in case you can use it with a local SIM card to receive or make important calls and switch to your smartphone to WiFi only," it said.

It also urged users to back up all contacts and important data in case they lost their phone.

"It advised consumers to always talk to their local service provider before travelling overseas so that they are aware and fully informed of all relevant charges that may apply.

In another development, CFM chairman Megat Ishak Maamunor Rashid said CFM had received 248 complaints over both international voice and data roaming charges in the first seven months of 2016.

It received a total of 90 complaints in 2015 and 87 the year before that.

He said CFM would continue to increase its efforts to ensure that consumers were well-informed and not shortchanged by continuously monitoring the service delivery of telecommunication service providers.

It would also address any breaches of the General Consumer Code of Practice for the Communication and Multimedia industry in Malaysia, he added.