Certain mobile phones occasionally need an update to recognize changes to your carrier's network. While GSM-based cell phones will update coverage automatically as you change locations, digital phones — like Sprint or Verizon — need a manual update. The update, done over the air, often takes less than a minute. Referred to as a PRL (Preferred Roaming List) update, it ensures your cell knows which towers to use on the home and roaming network. Carriers do not charge for the update.
Press the "End/Power" button to turn your cell phone on. Ensure you are in an area with sufficient access to your carrier's home (not roaming) network. (Note the signal bars on your phone's screen, usually in the upper-right corner. Roaming is often indicated by the letter "R.")
Press *228 then "Send" (as if you are dialing a number), if you're using a phone from Verizon Wireless or Alltel. For Sprint phones, open the main menu and choose "Settings." Select "Phone Info," then choose "Update PRL." For other carriers, contact your provider for details on how to initiate the update.
Follow the automated prompts or wait to receive a confirmation on your phone's screen that the update is complete. Press the "End" key to return to the home screen.