US Area Code Listings by State

Browse US area codes organized by state. 52 states and territories listed alphabetically.

Why one state has 40 area codes and another has one

The number of area codes a state carries tracks how many phone numbers it needs, not how large it is on a map. California holds 40, Texas 29, and Florida 23. Ten states get by with a single code each. Wyoming and Alaska cover enormous ground but have few people, so one code is enough.

The split goes back to the original 1947 plan. AT&T gave states that needed only one area code a middle digit of 0, and states large enough to need several a middle digit of 1. That is why 605 (South Dakota) and 212 (New York City) read so differently – the middle digit was a deliberate signal about how crowded the state's phone network was.

How a state runs out of numbers and adds a code

When an area code nears its supply of prefixes, the regulator adds capacity one of two ways.

Geographic split

The region is divided in two. One half keeps the old code; the other gets a new one. Everyone in the new half has to change their number. This was the standard approach for decades.

Overlay

A second code is layered over the same geography. Existing numbers stay as they are; new lines draw from the added code. The trade-off is that local calls then require all ten digits. Most codes added today are overlays.

States served by a single area code

Ten states still run on one code apiece. Dialing stays simple in these places – the code rarely matters because there is only one.