What Network to use in Philippines

Cali Cat wrote:

I don't believe you can select specific carriers. In some countries I've seen multiple carriers depending on which city I am in and what time of the day it is. If you want to lock into a specific carrier, you would need a SIM card from that carrier and your TMO phone needs to be unlocked.

In some countries T-Mobile has agreements with multiple carriers. In other countries they may only roam a single carrier. Also, it's possible that T-Mobile may restrict roaming on various carriers by region. Essentially, you need to look at their coverage map for the country in question. If you can roam where they show service, that's good. If you can't roam where they show service, then you should report the issue to T-Mobile. It doesn't hurt to try to connect to a different roaming partner if the one the phone picks does not work well for you.