The Preferred Roaming List, also known as PRL, is a list of frequency bands that the phone is allowed to access throughout the country. The PRL directs the phone to access one particular band over another first. If that signal is weak, it will then direct it to access another signal from another cellular provider which may result in roaming fees. The PRL is stored in the phone's memory. You can update the PRL in a MetroPCS mobile device by connecting to the phone's update feature.
Power on the MetroPCS phone.
Dial "*228" on the phone.
Choose option 2 and follow the prompts to update the phone.