If you are using iPhone 4 CDMA or iPhone 4S and updated it to iOS 6, I will show you the way to successfully unlock 3.0.04 baseband which is only on that devices.
It is now a secret that after iOS update your iPhone baseband changes too. If you are our regular reader than you may know that I prepared for you iOS 6 baseband overview where you can find out what baseband your device will have after update to the 6 generation of Apple iOS. And the iPhone 4 CDMA and iPhone 4S baseband is 3.0.04, so let’s unlock it.
According to sources 65 percent of iPhone users have successfully updated their gadgets to iOS 6. Some of them did it on purpose, and some trough negligence. It is clear that if you use iPhone being unlocked unofficially you will lose unlocking status after update. It is very sad but what can we do except to be careful and always remember this.

 Unlock 3.0.04 Baseband Using Gevey Sim or R-Sim

If you use R-Sim 3 or Gevey Ultra S on iPhone 4S than don’t even think to update your iOS because it is confirmed that R-Sim or Gevey Sim don’t support iOS 6. The same situation with iPhone 4 CDMA. These Sim card unlocking methods don’t work on 3.0.04 baseband so don’t rely on them. Also there is news that Apple N Berry company is preparing new unlocking solution for its clients and I know that they will use IMEI unlocking code which will be more expensive that other offers. Now let’s talk about free possibilities to unlock that baseband.

Unlock Baseband 3.0.04 Using SAM Tool

Also it is no sense to talk about any free solution to unlock your iPhone 3.0.04 baseband. Do you know many free unlocking solutions for iPhone 4S or iPhone 4 CDMA? As for me I know only one tool that can unlock it. Do you remember SAM?
Yes, it is true. You can unlock even 3.0.04 baseband using SAM but only if you used SAM tool before on your iPhone and have your SHSH blobs saved before Apple company closed that possibility.

Unlock 3.0.04 Baseband Using IMEI Unlocking Code

So, as you can see the situation is critical but not hopeless. There is one method that you can use and this method is the best of all other methods about which you have ever heard before. I’m talking about IMEI unlock.
Unlocking solution which uses IMEI number of iPhone is the best because of one reason. If you try it you will get permanent factory unlock which means that you can update your iPhone to iOS 7, 8, 9… not worrying about losing unlocking status.
IMEI unlocking method supports any iOS firmware including iOS 6, any iPhone model, including iPhone 4 CDMA and iPhone 4S and any baseband version including 3.0.04.
The only negative to this that is it paid method. However, browsing the net and discovering many IMEI unlocking services.

Via : letsunlockiphone