Via SMS
Just type ROAM OFF and send it to 333.
Via WEB
Log-in to www.smart.com.ph/connect. For first time users, please register your account first. (Once logged-in, if asked what you would like to do, select "Browse Web Connect Services" from the options.)
Select SERVICES from the left sidebar menu.
Select International Roaming and deactivate this service option.
Via SIM SETTINGS MENU
Go to the SMART Menu.
Choose SIM Settings (or SIM Connect).
Select Roam to deactivate your international roaming service.
Prepaid international text roaming allows you to send and receive SMS messages and SMS VAS but disables your voice features. Original subscriber profile shall only be restored upon feature deactivation.