When you take your smart phone overseas and turn it on, it might start downloading emails and using the foreign data networks at your carrier’s roaming rates!
How To Turn Off Auto-Data Roaming In Android Phones
In your Android smartphone, go to “Settings”, “Wireless & Networks”, “Mobile networks” and uncheck “Data roaming” at the top before you take your phone overseas to prevent Silent Roaming.
In the US, this function is ok to have because it gives you better coverage on partner networks BUT left on when you arrive abroad and your phone will start downloading emails and data at roaming rates on whatever foreign networks it finds – at your carrier’s roaming rates for that country.
I’ve just done it to my phone, thanks for the instructions.