As far as I know any GSM sim card is capable of roaming. There are Postpaid subscribers who are using LTE enabled sim cards are able to use it abroad. So I don't see any difference here. You can try dialing on your mobile device *143# and check if GROAM option is available to enable it. You can also activate roaming by simply text GROAM ON and send to 2884. If you want to activate your roaming service only for a specific period, just text GROAM ON to 2884. Example: GROAM ON 06/18/2013 27.
While you're still in the Philippines, we highly suggest that you activate your roaming service at least 24 hours before your flight's departure time. However, you can also register as early as seven (7) days before leaving or as late as an hour before your flight.
Your GROAM request status will be tagged as “Pending” when you activate it in the Philippines. Your request will only be approved once you arrive at your destination. This means, while in the Philippines, you can still enjoy local services such as
data browsing, promos, DUO, Share-a-Load and ring back tones. These services will be unavailable once you reach your destination and get your roaming signal activated.
Upon arrival at your destination, you will receive a message to confirm if you would like to activate your roaming. You will be given 24 hours to confirm. During that 24-hour period, your roaming will be active and your transactions will be charged at regular roaming rates.
- Reply GROAM YES: If you would like to activate your roaming. Roaming SMS charges will apply.
- Reply GROAM NO: If you would not like to activate your roaming. Roaming SMS charges will apply.
- No Reply: If you do not reply within 24 hours, your roaming will be deactivated.
Within the 24-hour period, you will first receive 3 SMS notifications asking if you would like to activate your roaming. These SMS notifications are free of charge.
For more information, you can refer at this link GROAM | Roaming | Help and Support.