Look Up Any US Area Code

Type an area code, city, or state to see where it is, what time it is there, and which cities and carriers it covers. 370 US area codes, plus international and toll-free.

Try “212”, “Houston”, or “New Jersey”

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Area codes don't stop at the US border

The North American Numbering Plan covers 467 active area codes. The US holds 370 of them. Canada has 56. The remaining 41 cover Caribbean nations and Pacific territories.

Inside the US, California leads with 40 area codes, followed by Texas (29), Florida (23), New York (22), and Illinois (17). Eleven states run on a single area code. No US code crosses a state line – three Canadian codes do.

How a North American phone number is built

Every number in the plan follows the same 10-digit structure. AT&T and the Bell System introduced the format in the early 1940s to manage long-distance routing across the continent. Direct long-distance dialing didn't arrive until the early 1950s.

NPA – Area Code

The first three digits. NPA stands for Number Plan Area, which is what AT&T called each region in the original plan. Some NPA codes aren't tied to a place – 800 routes to toll-free numbers, 900 to premium-rate lines. Not all allocated codes are currently in service.

NXX – Prefix

The middle three digits identify a telephone exchange within the area code. Carriers reserve number blocks by claiming an NXX within a given NPA. Not every prefix is assigned, and not every assigned prefix is active.

XXXX – Subscriber number

The final four digits distinguish individual lines within an exchange. Each active NPA/NXX pair can hold up to 10,000 subscriber numbers. Across all current allocations, the system has room for roughly 1.7 billion unique numbers – about four per person in the US and Canada combined.

Landlines are still a bigger part of the system than you'd expect

More than two-thirds of active prefixes are still allocated for landline use. The CDC's National Health Interview Survey – the standard source for this data – found that as of July–December 2024, roughly 76% of US adults live in wireless-only homes, meaning about 1 in 4 households still has a landline. In 2010 that ratio was reversed: 72% of households had one.

Donut chart: 76% of US adults live in wireless-only homes, 24% in homes with a landline (CDC NCHS, July–December 2024)

Businesses, home internet services, and VoIP systems account for a large share of the remaining landline traffic. A single business location can hold dozens of numbers – fax lines, direct-dial extensions, automated systems – all within the same area code.

A cell number keeps its area code wherever you move

Mobile phones use the same numbering plan as landlines. A cell number is NPA-NXX-XXXX, with the same area code in front – there is no separate system for wireless. What changes is what the code tells you. For a landline, the area code marks where the line is installed. For a cell phone, it marks where the number was first issued.

Since number portability arrived in 2003, people keep their number when they switch carriers or move across the country. Someone who got a 212 number in Manhattan can carry it to Texas and keep it for years. So when you look up a mobile number here, the area code points to where it was registered, not where the person is calling from today.

Some area codes don't belong to any place

Not every area code maps to a geography. Several are assigned for specific call types regardless of where the call starts or ends.

Toll-free

The called party pays; the caller isn't billed for long distance.

800 833 844 855 866 877 888

Premium-rate – 900

Calls billed to the caller at above-standard rates. The 900-number industry peaked in the late 1980s and early 1990s, then collapsed after legislative changes in the mid-1990s restricted the billing practices that made it work.

Other non-geographic codes

Codes in the 500s and 600s – including 500, 521–529, 533, and others – once handled dial-up modem access and security systems. Most see little traffic now. 600 and 700 are reserved for specialized telecommunications services.

Finding what you need

If you have a number and want to know where it's from, search by area code – you'll get the primary city, state, timezone, and a map of the coverage area.

If you're starting from a city or state, the search bar handles that too. Type a place name and it'll surface the area codes that serve it.

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