When you obtain an unlocked cell phone, you can use the cell phone on any Global System for Mobile Communications (GSM) network, as long as you have a Subscriber Identity Module (SIM) card from the GSM carrier you plan on using with the phone. In some cases, depending on the GSM carrier or the model of your cell phone, you may have to alter menu settings in your phone to use certain features; such as text messaging, Internet, and voice mail. An unlocked cell phone can also be very useful when you travel to international locations, especially since you can buy an international SIM card and pay lower voice and messaging rates as opposed to the international roaming rates provided by your local GSM carrier.
Obtain the manual for your cell phone.
You may need to consult with your manual when you modify settings in your cell phone to make it compatible with your current GSM carrier.
- If a hard-copy manual was not included with your cell phone, you can obtain a copy of your manual from the cell phone manufacturer’s website or at the website of the cell phone’s original GSM carrier. For example, if you obtained an unlocked cell phone that originated from T-Mobile, but you plan on using the phone with ATT, visit T-Mobile’s website to locate a copy of the cell phone’s manual.
Place your SIM card into the phone.
An unlocked cell phone will allow you to use a SIM card from any GSM carrier in the phone.
- Refer to your manual to determine how the SIM card is inserted into the cell phone. In most cell phones, the SIM card slot will be located in the back compartment near the battery.
Power on your cell phone.
After your cell phone is powered on, your SIM card will connect to your carrier’s nearest GSM tower and you will have the ability to make and receive phone calls.
Text Message Settings
Determine your carrier’s text message service center number.
If you plan on sending and receiving text messages on your unlocked cell phone, you will need to program your carrier’s text message service center number into your messaging settings.
- Contact your GSM carrier directly or perform an Internet search to locate the correct text message service center number for your carrier.
- If ATT is your carrier, the text message service center number is +1-312-314-9810.
- If T-Mobile is your carrier, the text message service center number will be +1-206-313-0004.
Modify the text message service center number within your unlocked cell phone.
- Refer to your manual to determine where the text message service center number can be modified from within your cell phone. In most cases, you can navigate to your messaging folder and select “Settings” or “Message Settings,” then choose the “Text Messaging” settings folder to locate your messaging service center number.
Test your text messaging feature.
This will allow you to determine if you efficiently modified your text message settings and used the correct text messaging service center number.
- Send a text message to your own phone number from your unlocked cell phone. If you successfully receive the message, your text message settings are correct; however, if your message failed to send and you received an error message, you will need to contact your GSM carrier.
- Contact your GSM carrier and explain that you cannot send or receive text messages. Your carrier may be able to send you an over-the-air (OTA) update with the correct text messaging settings or walk you through steps to correct the error.
Determine the appropriate Access Point Name (APN) for your Internet service.
To use your carrier’s Internet service, you will be required to enter the correct APN information into your cell phone.
- Contact your GSM carrier directly or visit your carrier’s website to determine the correct APN information to enter into your unlocked cell phone. The APN information may vary greatly depending on your Internet package or cell phone model.
Enter your carrier’s APN information into your unlocked cell phone.
- Refer to your cell phone’s manual to determine where you can modify the APN information. In most cases, you can go to the “Settings” or “Browser Settings” sub-menus within your Internet folder to modify the APN information.
Test your Internet connectivity.
- Launch your browser or Internet from its icon or location on your cell phone to determine if it connects successfully.
- If your Internet does not connect successfully, try accessing more than one website to ensure that the connectivity issues are related to your cell phone, and not with one particular website.
- Contact your GSM carrier directly if your Internet does not work with the APNs you entered. You may be advised to modify your APN settings or they may send you an OTA update with the correct Internet or APN settings.
Voice Mail Settings
Obtain the voice mail messaging center number for your GSM carrier.
You will need to program the voice mail number into your phone if you want to access voice mail from your unlocked cell phone.
- Contact your GSM carrier directly to determine the number for the voice mail system. If your carrier is T-Mobile, the voice mail number will be +1-805-637-7243.
Program the voice mail number into your cell phone.
This will prevent you from having to enter the number manually each time you want to listen to your voice mail messages.
- Refer to your manual to determine how you can add phone numbers to your contact list or program your voice mail number into your speed dial.
Test your voice mail from the unlocked cell phone.
- Dial your voice mail number to verify you can access your voice mailbox. Depending on your voice mailbox settings, you may need to enter a password to access your voice mail.