How to Unlock CDMA Cellphones

By Dan Harkins

CDMA cell phones, which run on "code division multiple access" technology, compete with GSM phones that use "global system for mobile communications" technology. AT&T and T-Mobile use GSM, and Verizon Wireless, Sprint and Virgin Mobile use CDMA. And all can be locked to prevent you from venturing to another service carrier. If you'd like to take your CDMA phone to a better deal on another network, or to avoid roaming charges, you'll have to ask the original service provider for a free unlock code. Otherwise, you'll have to buy one at an online retailer, which is a legal process.

Things You'll Need

  • IMEI number

Step 1

Write down your 15-digit IMEI (International Mobile Equipment Identity) number. Find this by removing the back cover and battery of your phone and looking on the label underneath, or by pressing "*#06#" then "Send" on your CDMA phone. The number should appear on the screen.

Step 2

Call the old carrier's customer support line, provide your IMEI number to a representative and learn whether you qualify for a free unlock code. If you don't know the CDMA phone's former carrier, contact the phone's manufacturer and they should know to which network the phone is locked. If you're not granted a free code, navigate to one of several online unlock code services, where you'll enter your model, IMEI and network information and pay upwards of $9.99 for a code -- as of October 2010.

Step 3

Slide your old SIM card from its slot beneath or next to the battery on your CDMA phone. Return the battery and power on your phone.

Step 4

Enter the unlock code into your CDMA phone, then click "Send" -- if instructed to do so. A message will let you know if the unlock worked.

Step 5

Turn off your phone and slide your new service provider's SIM card into its slot underneath or by the battery. Replace the battery and back cover, then you're ready with a new plan in place.