How to use Cydia to Jailbreak and unlock your iPhone
If your iPhone came locked to a specific carrier, and you want to use a different carrier, there are several ways to do so. Probably the safest way to do it is through official means, by contacting the new carrier (many carriers want you to switch, and will take care of the issue for you) or asking your current carrier to unlock the iPhone for you as you’ll need to travel abroad. Some carriers are more flexible than others in this regard. If this option is not on the table, you can also go through paid services online. These vary in terms of pricing and safety, with some sources being reliable, while others are anything but. If you go down this route, make sure you check feedback on the service, read posts on iPhone forums, and generally do your homework. You don’t want to risk losing money over a service that doesn’t work.
That being said, you can also take care of business yourself, and unlock your iPhone using Cydia. Cydia is essentially a third-party application that gives you access to apps that are not supported by Apple. Using Cydia expands beyond the advantages of unlocking your iPhone from certain carriers, as it also gives you access to apps and customization options previously unattainable. In order to use Cydia, you’ll need to have an iPhone that went through the jail-break process. If this is not the case, worry not! Most jail-break apps come with Cydia bundled up, so you don’t have to worry too much. A prime example of an easy to use jail-breaker with Cydia support is redsn0w. Regardless of your choice in this regard (there are too many programs to list, many of these are tailored to specific iPhone models), you’ll need to jail-break your iPhone before you can use Cydia and unlock your phone entirely.
Before attempting to unlock your iPhone through Cydia, make sure to back-up all your data. While this is not an exceptionally complicated process, things do sometimes go wrong, and it’s better to be safe than sorry. Another important aspect to consider when unlocking your iPhone is firmware. Don’t update to newer firmware versions until the unlocking process is completed, as you can run into various errors. Whatever happens, know that you can restore your phone to its previous state at any time, so there’s not a huge risk in unlocking an iPhone through Cydia. Once Cydia is installed, everything is backed-up and you’re ready to go, switch to your new carrier’s SIM card, turn the iPhone on, turn 3G off, switch to your local wireless network and launch Cydia.
In Cydia, go to the Manage section, tap Sources and then Edit, press Add and insert the URL repo666.ultrasn0w.com (there are other alternatives to ultrasn0w, but we recommend using this as it’s a tested and safe method). Once that’s done, you’ll see the new URL in the Sources tab, under the Entered by User section. Tap it, and then tap on ultrasn0w to install it. Once it’s done installing, you’ll have to reboot your iPhone. This is the last step, as once the iPhone has booted up again, it should already recognize your new carrier. That’s it, you’re good to go! Easy, fast and completely free! You are now the owner of an iPhone, unlocked to any carrier, and you can continue to use Cydia to download any app that you might be interested in. Enjoy!