However, within four years, 210 was already close to exhaustion because of San Antonio's rapid growth and the popularity of cellular telephones and pagers.
Most of Bexar County stayed in 210, while the San Antonio suburbs and the Hill Country were split off as area code 830.
Amid projections that 210 would exhaust by mid-2018, the Public Utility Commission of Texas approved a new all-service overlay.
Area codes 210 and 726 serve most of Bexar and small portions of Atascosa, Comal, Guadalupe, Medina, and Wilson counties.
The numbering plan area includes the following cities and towns: Adkins, Alamo Heights, Artesia Wells, Atascosa, Castle Hills, Cibolo, Converse, Ecleto, Elmendorf, Helotes, Kirby, Leon Springs, Macdona, Olmos Park, Saint Hedwig, San Antonio, Shavano Park, Schertz, Terrell Hills, Universal City, Von Ormy, Wetmore, and Windcrest.