Section
Area Codes
Where an area code comes from, which state or metro it covers, and the split-and-overlay history behind it -- not just which city it's in.
Index
01 Every Texas Area Code, and the Overlay Stack Behind Each Metro Texas has 29 area codes today. Dallas alone stacks four on the same footprint. Here's the full list, plus how Houston, San Antonio, and Austin overlay theirs too. 02 All 41 California Area Codes, Plus the Family Tree Behind LA's Seven All 41 California area codes, mapped to region and year in service, plus how LA split and overlaid its way from one 1947 code, 213, to seven today. 03 Every Michigan Area Code, and the Split Tree Behind Detroit's Newest Michigan has 13 area codes today, seven descended from Detroit's original 313. Here's the full list, plus the split-and-overlay chain behind each one, including the newest, 679. 04 Every New Jersey Area Code, and the Day Three of Them Launched at Once New Jersey has 10 area codes today, all descended from a single statewide code assigned in 1947, including three overlays the state's utility board activated on the exact same day in 2001. 05 Every North Carolina Area Code, and the One About to Get Company North Carolina has 10 area codes today, all descended from the single code assigned to the whole state in 1947, and regulators are now weighing an overlay for the one region still running on just one. 06 How US Area Codes Actually Work A US phone number has three parts, not one. Here is what each part actually identifies, why New York got 212 specifically, and the real difference between a "split" and an "overlay." 07 Is There Really Such a Thing as a 'Scam Area Code'? Short answer: mostly no. Scammers fake your own area code ("neighbor spoofing"). The one real exception: ten NANP codes tied to the "one ring" scam. 312 Chicago Area Codes: 312, 773, 872, and How 312 Became an Island 312 used to cover all of Chicago and its suburbs. Two splits and an overlay later, it's an enclave, surrounded by 773, inside the same city. 09 New York City Area Codes: All Eight, Plus the Manhattan Block Wired Into the Bronx NYC runs on eight area codes split into two separate overlay stacks (one for Manhattan, one for the other four boroughs), except for the Manhattan neighborhood that uses neither. 404 Atlanta Area Codes: 404, 770, 678, 470, 943, and the Three That Stopped Taking New Numbers Atlanta runs on five area codes. Three, 404, 678, and 770, ran out of numbers to give out: existing lines still work, but nobody gets a new one from them. 305 Miami Area Codes: 305, 786, 645, and the 1947 Code That Once Covered All of Florida Miami-Dade and the Florida Keys share three overlapping area codes today. 305 is the original, dating to 1947, back when it covered the entire state of Florida, not just Miami. 702 Las Vegas Area Codes: 702, 725, and the Split That Sent the Rest of Nevada to 775 Las Vegas runs on two area codes today, 702 and 725, but 702 alone covered the entire state of Nevada for more than 50 years before growth split off everywhere outside Clark County.