Fixed voice lines used by consumers appear to have fallen since June 2000. Overall fixed voice lines have fallen as well since then. All that would lead a rational observer to conclude that fixed voice lines sold to small and medium-sized businesses have fallen as well. But that is not in fact correct.
Fixed voice lines sold to business customers have increased from about 45.7 million to about 64.6 million in December 2007, according to the latest Federal Communications Commission data.
What is not clear is the degree to which mobile voice lines have affected overall enterprise or SMB voice lines in service. Since 2001 wireless voice accounts in service have increased from 124 million to 249.3 million. A reasonable assumption is that business use of mobile voice has accelerated since 2001.
Researchers at IDC reported in 2006 that surveyed IT managers think nearly 30 percent of their supported employees use their mobiles as their primary work phone. About 41 percent of wired voice lines are used by business customers. If the same percentage of wireless devices likewise are used primarily in business mode, then there are about 102 million wireless devices used in a business mode.