Wireless substitution is the process of canceling landline phone service and relying solely upon mobile phone service. The trend toward wireless substitution is known as fixed-mobile substitution (FMS).
In 2012, a study from USTelecom reported that 39% of households within the United States were mobile-only. In addition to homes that had no landline at all, another 18% reported that although they had a landline they did not use it at all.
A related trend, cord cutting, includes both wireless and VoIP substitution for landline service, as well as the cancellation of traditional television services, usually in favor of less expensive options.