Once you have purchased Roam Boost, the data balance and expiry will be reflected in the homepage of your Circles.Life app, under Home > Roaming /IDD.
When you exceed the data volume for the Roam Boost that you purchased, you will be charged at pay-per-use data rates for the country that you are currently roaming at.
To avoid incurring pay-per-use data rates, simply purchase another Roam Boost before you use up your data!
*IMPORTANT advisory*: For users using Roam Boost B in the USA, please note that the data may only be used in US Mainland, and is NOT applicable in other US territories, e.g. Guam.