Samsung SCH-8500 User Manual page 7

If you received your phone in the mail, you need to unlock it
before you begin making calls. Just enter your four-digit lock
code, and you'll be ready to begin making calls. This code
typically is the last four digits of your Sprint PCS Phone
Number, Social Security number, or tax ID number.
If you need help please call Sprint PCS Customer Care at
1-888-211-4PCS (4727). You can also press
TALK
Shift
from your activated Sprint PCS Phone. A Sprint PCS
Customer Advocate will answer (24 hours a day, seven days a
week) and be happy to assist you.
Our services are provided to you under certain terms and
conditions — all of which are listed in the brochure included
in your Sprint PCS Phone Box.