Area codes 336 and 743 are NANPA area codes which cover most of north-central and northwestern North Carolina, mainly the Piedmont Triad region and the northern Foothills and northern Mountain regions. It was created out of area code 910 on December 15, 1997.
Officials from the North Carolina Utilities Commission announced on August 20, 2014 that 336 would be overlaid with a new area code, 743. The new area code made local calls require 10-digit dialing. However, no long-distance charges will be applied within the 336 territory. Those who already have 336 numbers kept them, easing the burden from having to change their phone number. The new area code will be used primarily for issuing new numbers, and was needed because 336 was projected to exhaust some time in 2016. The activation of 743 broke seven-digit dialing throughout the I-85 Corridor in North Carolina; Charlotte (704/980) and the Triangle (919/984) have already been overlaid. At the time, 336 was one of the few urbanized area codes without an overlay, making the Triad one of the few large metropolitan areas in the South where seven-digit dialing was still possible.
The 743 area code entered service on October 24, 2015; permissive dialing began on that date, and continued until April 23, 2016 when ten-digit dialing became mandatory. The first numbers with a 743 area code were issued in May 2016.