Where in North America is area code 703?

Las Vegas and most of Clark County, Nevada.

The 702 area code is used to dial to the following cities in Nevada:

Las Vegas, Henderson, Laughlin, Sunrise Manor, Boulder City, Cal-Nev-Ari, Indian Springs AFB, Mesquite, Moapa, North Las Vegas.

Until 1999, area code 702 served the entire state of Nevada.

In 2014, area code 702 will be overlaid with area code 725, serving the same cities.