To unlock or Not unlock?

[Michael_psgn21]

I recently got an iPhone 3GS and I wanted to unlock it.... it's on iOS version4.1, the Firmware is 6.15.00 and the serial is QR1352T1EDG... should I upgrade to 5.1.1 and try to unlock it so I can use my T-Mobile sim card? Also can someone tell me if my iPhone is able to get unlocked because I've read and seen videos online saying to not unlock an iPhone if it's produced after 2011 so I want to know if I should.

Thank You!

[tehh4ck3r]

Yes, you can unlock it if your baseband is 06.15.00

To update to 5.1.1:

Download the latest version if iTunes and the iOS 5.1.1 firmware for the 3GS
Download the latest version of redsn0w
Create a NO_BB ("no baseband") custom IPSW using redsn0w- open redsn0w, click "Extras", and click "Custom IPSW"
Enter pwned DFU mode- In redsn0w, go back to the Extras menu and click "Pwned DFU".
Open iTunes and hold down the "Shift" key (on Windows) or "Option" key (on Mac) and click on Restore.
Navigate to your custom IPSW (the NO_BB ipsw) and select it.
Then continue with the restore as normal.

Afterwards you can jailbreak with Absinthe and unlock with ultrasn0w

[Michael_psgn21]

it asked me about a boot rom? it said i can know by my serial number but my serial number starts with a QR instead of numbers so idk if I have the new or old boot rom? can you tell me which boot rom I have?
(Sorry I'm New To iPhones lol)

[Error3194]

Unlocking doesn't matter according to new or old bootrom. It is a big misconception, what you need to look at is the 135 in your serial number this means you phone was built on the 35th week of 2011. They said you the new Toshiba chips didnt come til the 45th week so flashing 06.15.00 you will be safe
**Sorry I did not read your phone already has 6.15.00, rejailbreak and install ultrasn0w and you should be good, if you get searching you may need to reflash your 6.15.00 baseband or downgrade to 05.13.04