How to Unlock a Samsung Phone

Contact your carrier

Call the carrier and ask about the unlocking policy. Most carriers will agree to unlock after the user has used the phone for a certain period of time or when the contract expires. If the contract is still active then they will likely ask you to pay an early termination fee to unlock the phone.

They may unlock it early if you explain that you're going abroad on business and need to use your phone.

Contact the carrier you intend to change to. Many carriers are willing to unlock your phone if you switch from one of their competitors. Call the carrier you want to change to and try to negotiate whether or not you will be supported in unlocking your phone if you use their service.

You need to make sure that your new service provider uses the same network type that your phone supports. In the US, GSM (AT&T, T-Mobile) and CDMA (Sprint, Verizon) are the two main network types. In Vietnam, all major carriers today (including MobiFone, VinaPhone, Viettel, VietnamMobile) operate GSM networks.

Find the code for your Samsung phone. If the phone has been out for a while, the unlock code is generally provided by the manufacturer. Look for your phone model online to see if it has a code. With newer phone models, it will be almost difficult to find the code.

By paid unlocking service

Find your phone's IMEI/MEID number. You need to provide this unique identifier when requesting an unlock code. Open the calling app and use the keypad to dial *# 06# . A 15-digit code will appear on the screen.

Note down this code so you can easily re-enter it later.

Find a reputable unlocking service. There are many companies online that claim they can unlock phones for a fee. Since you're about to pay to have your phone unlocked, make sure the unlocking service has good reviews and a strong guarantee.

Code required. You will be asked to provide your IMEI/MEID number along with contact and payment information. The amount paid will depend on the phone model and code retrieval speed.

It can take up to several days to track down the code because these types of companies often rely on relationships with carriers.

When entering phone information into the service, you need to make sure these parameters are 100% accurate to be able to receive a code that works with the device.

Insert a new SIM card. After receiving the unlock code, turn off the phone and take out the old carrier's SIM card. Then, insert the new carrier's SIM. The SIM tray is usually located behind the battery or on the side of the device.

See online instructions on how to find and remove your SIM card.

Power on the phone. You will be asked to enter a code to connect your phone to the mobile network. Enter the code you received from the unlocking service.

You may have to be within coverage of the new network for the code prompt to appear. This process will vary depending on the device.

Check if the phone is connected. If the code just entered is correct, the phone will connect to the new mobile network. If you can't connect to the new network, you need to make sure you're in coverage area, then contact your carrier to see if your phone is properly unlocked.

Unlock Samsung Galaxy S3 and Note 2 manually

You need to make sure your phone is up to date. Your phone needs to run Android 4.1.1 or higher to apply this method. You can check your device's version by opening Settings, scrolling to the bottom, and selecting About Device. The version will appear below the Android Version heading.

To update your phone, open Settings and scroll down to About Device. On the next menu, select System Updates and tap Check for Updates. The phone will search for available updates, if available, the system will automatically download and install them.

This method is not applicable to devices with custom ROM pre-installed.

Open the calling app. You need to enter the code into the dialer to open the Service menu. Once the dialer opens, enter the following code:

*#197328640#

Select "[1] UMTS". Once the code is entered, the phone will automatically open to the ServiceMode menu. Here, select "[1] UMTS".

Tap an option in the on-screen menu. If you accidentally choose the wrong one, you can press the Menu button on your phone and select Back.

Open the Debug menu. On the UTMS menu, select "[1] DEBUG SCREEN". On the next Debug menu, select "[8] PHONE CONTROL". Finally, select [6] NETWORK LOCK from the Phone Control menu.

Select "[3] Perso SHA256 Off". Wait about 30 seconds, then press the Menu button and select Back. Click on "[4] NW Lock NV Data INITIALLIZ".

Wait and reboot. After selecting "[4] NW Lock NV Data INITIALLIZ", wait about 1 minute and then restart the phone. There will be no confirmation message that the process was successful, so you need to check by inserting a new SIM card. If the phone does not ask to enter an unlock code, you are successful.

If this method doesn't work on your phone, contact your carrier about the unlocking issue or pay for an unlocking service to receive the code.

Unlock Samsung Galaxy S4 manually

You need to make sure your phone is suitable for this method. This method only applies to Galaxy S4 from AT&T and T-Mobile in the US. Besides, the device must be a pure phone; Android with custom ROM will not be compatible.

This method is almost inapplicable to CDMA phones such as those from Sprint and Verizon in the US.

Open the calling app. You need to enter the code into the dialer to open the Service menu. Once the dialer opens, enter the following code:

*#27663368378#

Select "[1] UMTS". After you enter the code, your phone automatically opens to the ServiceMode menu. Here, select "[1] UMTS".

Tap the menu option on the screen. If you make the wrong choice, you can press the Menu button on your phone and select Back.

Service Mode is a very powerful phone diagnostics menu. You should only change specific settings as described in this guide. Any other changes may cause the phone to become inoperable.

Open the Debug menu. On the UTMS menu, select "[1] DEBUG SCREEN". Next on the Debug screen, select "[6] PHONE CONTROL". Finally, click "[6] NETWORK LOCK" on the Phone Control menu.

Select "[3] Perso SHA256 Off". After you have made your selection, the screen will display this content:

SHA256_ENABLED_FLAG[1]SHA256_OFF => SHA256_ON

Click on the first line. After you tap the "SHA256_ENABLED_FLAG[1]" option, your phone displays:

MENU NOT EXPRESS BACK KEY

To continue, press the Menu button on your phone and select Back.

Make sure the settings are changed appropriately. When you back up, the message in step 4 will display:

SHA256_ENABLED_FLAG[0]SHA256_OFF => Not Change

Return to the UMTS menu. Press the Menu button and select Back four times until you return to the UMTS main menu. Then, select "[6] COMMON" then tap "[6] NV REBUILD". The screen will display the following message:

Golden-Backup existsYou can Restore Cal/NV

Restore backup. Select "[4] Restore Back-up" on the NV REBUILD menu. The phone will reboot automatically. Now that your phone is unlocked, you can insert your new carrier's SIM card. If the device does not ask to enter an unlock code, it means the process was successful. Check if you can connect to the mobile network.

If this method doesn't work on your phone, contact your carrier about the unlocking issue or pay for an unlocking service to receive the code.