Can I use a Sidekick with _______ carrier?
Can I use a Sidekick in _______ country?

The short answer is...no.

NEWS: You may be able to get a Sidekick at home! Check on the International Sidekick Carriers page

If you are not in one of the countries listed in the International Sidekick Carriers page, please keep reading.

The T-Mobile Sidekick 3 is locked to T-Mobile USA. Due to several reasons, technical and legal, T-Mobile will not give out unlock codes for the Sidekick 3, the Sidekick iD, any Limited Edition Sidekick, or any older Sidekick device.

Something that is very important to understand about the Sidekick is the server architecture necessary to support it. The Sidekick is unlike any other wireless device because it automatically (and securely) synchronizes with T-Mobile's servers, which allows you to be able to recover your information if something happens to the Sidekick and it has to be reset to fix the problem. This back-end hardware is proprietary (to Danger, in fact), and it must be in place for the Sidekick to work.

If you take away the data servers away, two things will happen to your Sidekick:

1. You will only be able to make phone calls and send text messages (no email, no Internet, no ringtone downloads, no games)
2. Your Sidekick will throw error messages at you all the time because it wants to connect to that data server and it can't

If you take a Sidekick to a different carrier (if it could even be unlocked to do that), you would probably end up with the problems just above: No data and lots of error messages. It wouldn't be pretty.

Now, you just might be able to unlock your Sidekick 3 without getting a code from T-Mobile, but be very careful--if it's not Danger or T-Mobile, it might not be legit. Once again, T-Mobile will not unlock Sidekick devices.