Most phones will automatically configure themselves to access data on T-Mobile's US network, however some Android phones need to be configured manually.
If you have an Android phone (such as an HTC):
- On the home screen, press MENU, then Settings > Wireless & networks
- Then go to Mobile networks > Access Point Names
on the APN (Access Point Names) screen, press MENU and tap new APN
- In the APN field, enter epc.tmobile.com (if that doesn't work try internet2.voicestream.com or wap.voicestream.com)
- Leave the username and password fields blank
- Press MENU and tap Save
Please note that you must be on T-Mobile's network in order to access data services. Internet access is not available when roaming on partner networks.