How to: Unlock Samsung Galaxy S4
Prerequisites to unlock your S4
1. Dial *#06# to find your IMEI number
2. Purchase you unlock code here: Samsung Galaxy S4 unlock codes
3. Your code will be emailed to you
Supported Carriers and Variants
These instructions will help you unlock a Galaxy S4 (GSM versions only) from a supported carrier (including AT&T, T-Mobile, MetroPCS, Rogers, Telus, Bell and many more). This includes the variants like the Galaxy S4 Active and Galaxy S4 Mini.
Unlock Procedure: Use your new SIM card to unlock your phone!
1. Insert a SIM card from a new carrier (not the one the phone was locked to) and turn on your phone, you will be prompted to enter your unlock code.
2. Enter the entire 8 or 16 digit unlock code that you received by email and then press unlock. If you don't already have a code, you can order your Samsung unlock code here: Unlock Galaxy S4.
3. There is no step 3! You should now be able to use your phone on any GSM network
About the Galaxy S4
The Galaxy S4 debuted on April 26 2013 and was a breakaway success for Samsung. Samsung sold 10 million units within the first month making it the fastest selling Smartphone is Samsung's history at that time. Samsung released several different models of the phone across international markets including the SGH-M919, SGH-I337, GT-I9500 and GT-I9505. The initial release supported Android 4.2.2 (Jelly Bean) but there have been subsequent updates for 4.4.4 (KitKat) and 5.0.1 (Lollipop) in select markets.
Troubleshooting (Android 4.2.x and lower only!)
If you get an error message that says "network unlock request unsuccessful" don't panic, it is very common and can be easily remedied. Follow the steps below to get your code working. The steps are somewhat technical so follow them carefully. Note these steps do not apply if you are running Android 4.3 or newer.
- Go to the Dial pad and dial *#0011#
- Press your MENU button (Bottom LEFT button) and click BACK on the menu that appears, Nothing will happen do not worry please move to the next step
- Press your MENU button AGAIN and this time click KEY INPUT
- When the Key input box appears please input the number "1" and hit OK
- You will see a number 1 for a while (up to a minute), please wait until it changes into the SERVICE MENU
- Select  UMTS >  DEBUGGING SCREEN >  Phone Control >  Network LOCK
- You will see 3 OPTIONS within Network LOCK
- Select the number  Perso Sha256 INFO, the screen will change slightly
- Press the MENU button then when the menu pops up please carefully hit BACK to return to the previous screen
- Next Select the number  Perso Sha256 ON, the screen will change again to a one line message
- Restart the phone on the screen by holding the power button and selecting RESTART
- When the phone prompts youfor the unlock code simply enter the unlock code provided to you