Why do I have to dial 10 digits to make local calls?

This is a restriction imposed by the FCC, related to area code changes in a given area.
While not required for use in all areas at this time, the prevalence of 10 digit dialing is
rapidly increasing across the United States, and is not unique to any one provider. Some
areas have multiple area codes that cover the same physical location. This is the primary
reason for 10 digit dialing.