First, make sure that before leaving the country, you update your account & settle unpaid balance.
Once you’re already out of the country, you will receive a welcome message with a link to Smart’s Data Roaming Manager. Here, you may subscribe to a data roaming package that suit you. Turning on your mobile data abroad without subscribing to a data roaming pack will automatically register you to Roam Surf 550 for your convenience.
For more info and the available roaming packages, you may visit https://smart.com.ph/World/traveling-the-world/dataroamingmanager