Numbering Resource Utilization in the U.S. (As of 06/30/00)

In recent years, a rapidly increasing demand for telephone numbers has required numerous area code splits, overlays, and number conservation measures.  In this report, we summarize the first systematic collection of comprehensive data on the utilization of telephone numbers within the United States.  The underlying information was acquired from carriers holding numbering resources as part of our ongoing assessment of the efficacy of numbering resource optimization measures.  In general, the reported data show that, of the more than 800 million numbers held by carriers that reported, about 44% are assigned to subscribers and in active use, about 47% are available for use, and the remaining 9% are dedicated to administrative and other purposes.