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NANPA Official Numbering Directory

US Area Code Directory & Lookup

Search all 335+ geographic area codes across the United States, toll-free prefixes, and North American partner territories. Look up assigned states, regional cities, overlay codes, and timezones to verify unfamiliar numbers before picking up.

Showing 468 of 468 codes
Area CodeState / EntityCoverage Region / Major CitiesOverlaysIn-Service DateTimezone
(201)New JerseyNorth-east New Jersey (Bergen County and Hudson County)
551
1947Eastern (ET)
(202)District of Columbiaall
771
1947Eastern (ET)
(203)ConnecticutSouth-west Connecticut (Bridgeport, Danbury, New Haven, Waterbury)
475
1947Eastern (ET)
(204)Canada (MB)Manitoba (all)
431584
1947International (+1)
(205)AlabamaWestern and central Alabama (Birmingham, Tuscaloosa)
659
1947Central (CT)
(206)WashingtonSeattle area1947Pacific (PT)
(207)Maineall1947Eastern (ET)
(208)Idahoall
986
1947Mountain (MT)
(209)CaliforniaPart of central California (Stockton, Modesto, and Merced, extending into central Yosemite National Park)
350
1958Pacific (PT)
(210)TexasSan Antonio metropolitan area
726
November 1, 1992Central (CT)
(212)New YorkBorough of Manhattan in New York City
332646917
1947Eastern (ET)
(213)Californiacentral area of Los Angeles
738
1947Pacific (PT)
(214)TexasDallas metropolitan area
469945
1947Central (CT)
(215)PennsylvaniaPhiladelphia area, including all its suburbs and parts of surrounding counties
267445
1947Eastern (ET)
(216)OhioCleveland area1947Eastern (ET)
(217)IllinoisCentral Illinois (Springfield, Champaign, Decatur, Urbana, Lincoln)
447
1947Central (CT)
(218)MinnesotaNorthern Minnesota (Duluth, Moorhead, Thief River Falls, Bemidji, Brainerd, International Falls)1947Central (CT)
(219)IndianaGary area1948Eastern (ET)
(220)OhioCentral Ohio outside of Franklin County (suburban Columbus)
740
April 22, 2015Eastern (ET)
(223)PennsylvaniaSouth-central Pennsylvania (Harrisburg, Gettysburg, Lancaster, York)
717
September 26, 2017Eastern (ET)
(224)IllinoisNorth and northwest suburbs of Chicago
847
January 5, 2002Central (CT)
(225)LouisianaEast-central Louisiana (Baton Rouge)August 17, 1998Central (CT)
(226)Canada (ON)Southwestern Ontario (London, Windsor, Kitchener-Waterloo, Cambridge)
382519548
October 21, 2006International (+1)
(227)District of ColumbiaWestern Maryland (Washington, D.C., suburbs; all counties which touch the Potomac River; Silver Spring, Hagerstown, Frederick, Rockville, Cumberland)
240301
June 14, 2023Eastern (ET)
(228)MississippiGulfport, Biloxi, Pascagoula, Bay St. Louis, and southmost MississippiSeptember 15, 1997Central (CT)
(229)GeorgiaSouthwestern Georgia (Albany, Valdosta, Bainbridge, Americus, Fitzgerald)August 1, 2000Eastern (ET)
(231)MichiganNorthwestern Michigan (Muskegon, Traverse City, Ludington, Petoskey)June 5, 1999Eastern (ET)
(234)OhioNortheastern Ohio (Akron, Canton, Youngstown, Warren)
330
October 30, 2000Eastern (ET)
(235)MissouriEastern Missouri (Columbia, Jefferson City, Hannibal, Cape Girardeau, Farmington, Lake of the Ozarks, Poplar Bluff)
573
March 24, 2024Central (CT)
(236)Canada (BC)British Columbia
250257604672778
June 1, 2013International (+1)
(239)FloridaSouthwest Florida (Lee County, Collier County, the mainland part of Monroe County, including Cape Coral, Fort Myers, Naples, and Everglades)March 11, 2002Eastern (ET)
(240)District of ColumbiaWestern Maryland (Silver Spring; Washington, D.C., suburbs; all counties which touch the Potomac River; Waldorf, Hagerstown, Frederick, Rockville, Cumberland)
227301
June 1, 1997Eastern (ET)
(242)BahamasThe Bahamas (all)October 1, 1996International (+1)
(246)BarbadosBarbados (all)July 1, 1996International (+1)
(248)MichiganOakland County
947
May 10, 1997Eastern (ET)
(249)Canada (ON)Ontario (Northeastern Ontario and Central Ontario: Greater Sudbury, Sault Ste. Marie, North Bay, etc.)
683705
March 19, 2011International (+1)
(250)AlaskaBritish Columbia (Victoria, Prince George, Prince Rupert, Kelowna, all areas except for Metro Vancouver and the Fraser Valley; and the isolated border town of Hyder, Alaska, US)
236672778
October 19, 1996Alaska (AKST)
(251)AlabamaMobile County, Baldwin County, Bay Minette, Jackson, Brewton, Citronelle, and a part of southwestern AlabamaJune 18, 2001Central (CT)
(252)North CarolinaGreenville, New Bern, Elizabeth City, Kinston, Outer Banks, Rocky MountMarch 22, 1998Eastern (ET)
(253)WashingtonTacoma, McChord Air Force Base, Fort Lewis, Lakewood, Auburn, Puyallup, Enumclaw, Spanaway, and the southern suburbs of SeattleApril 27, 1997Pacific (PT)
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Telecom Heuristics & Security

Why Robocallers Spoof Your Local Area Code (Neighbor Spoofing)

When an unfamiliar number rings your phone, psychological studies and telecommunications complaint data confirm that consumers are significantly more likely to answer if the Caller ID matches their own 3-digit area code (NPA) and 3-digit local central office exchange (NXX). Scammers exploit this cognitive bias through an attack vector known as neighbor spoofing.

How VoIP Dialers Inject Fake Caller IDs

Modern telemarketing operations rarely use physical copper lines. Instead, they operate SIP-based VoIP softswitches capable of placing thousands of concurrent calls per second. In standard SIP signaling, the caller can insert an arbitrary string into the From: or P-Asserted-Identity: header, transmitting whatever phone number the scammer chooses to display on your screen.

The STIR/SHAKEN Attestation Gap

The FCC mandated the STIR/SHAKEN cryptographic framework to sign caller identity. However, intermediate rogue gateway carriers frequently assign Attestation C (Gateway Attestation) or route unauthenticated traffic across non-IP network boundaries, allowing spoofed calls to reach subscriber devices without an outright carrier disconnect. For deeper technical analysis, read our guide on neighbor spoofing and STIR/SHAKEN.

The Caribbean +1 One-Ring Trap

Not all +1 phone numbers are domestic US calls. Under the North American Numbering Plan, several Caribbean islands share the +1 country code, including Jamaica (876), Dominican Republic (809, 829, 849), and Grenada (473). In the one-ring phone scam, autodialers ring your phone once and hang up, tricking you into returning an international toll call billed at $15 to $30 per minute.

On-Device Call Screening Protection

Traditional spam blocker apps require uploading your personal contact book to external cloud servers to detect numbers. In contrast, on-device call screening evaluates caller attestation, local number variance, and dialing cadence locally within the Android telephony subsystem, preserving complete personal privacy.

Frequently Targeted Area Codes

While robocallers rotate numbers dynamically across all 50 states, high-population metropolitan areas with numerous overlay codes experience the highest gross volume of automated attempts. To explore national complaint trends, review our research on what area codes receive the most spam calls and our breakdown of robocall definitions and prevention.

Frequently Asked Questions

Why do I get spam calls from my own area code?

Robocallers use a deceptive technique known as neighbor spoofing. Using automated VoIP dialing software, scammers manipulate the Caller ID to display your local 3-digit area code and often your exact 3-digit local exchange prefix. Because consumers are nearly three times more likely to answer an unfamiliar number from their own neighborhood, scammers spoof local codes to get you on the line.

What is an area code overlay?

An area code overlay occurs when a state utility commission and the North American Numbering Plan Administrator (NANPA) assign a new 3-digit area code to the exact same geographic territory as an existing code. Overlays prevent phone number exhaustion in dense regions without forcing existing residents to change their current telephone numbers, but they require mandatory 10-digit dialing.

Are calls from unfamiliar US area codes dangerous to answer?

Answering an unfamiliar call confirms to automated predictive dialers that your telephone line is active and monitored. Once an autodialer logs a human voice answering, your phone number is tagged as high-value in commercial lead databases and frequently resold across telemarketing networks, leading to a surge in daily spam calls.

Which area codes incur expensive international long-distance rates?

Several Caribbean nations participate in the North American Numbering Plan and share the +1 country code with the United States. Area codes like 876 (Jamaica), 473 (Grenada), 284 (British Virgin Islands), and 809/829/849 (Dominican Republic) look identical to domestic US area codes on Caller ID. Calling these numbers back can trigger international toll rates exceeding $15 to $30 per minute under the one-ring callback scam.

How does Callro stop spoofed area code calls?

Callro operates at the Android OS telephony layer via Android's native CallScreeningService API. When an incoming call arrives, Callro evaluates carrier attestation headers (STIR/SHAKEN), autodialer rotation velocity, and local exchange spoofing heuristics directly on your device. Confirmed spoofed robocalls are dropped silently before your phone rings, without uploading your personal contact book to cloud servers.

Stop Spoofed Local Calls Before They Ring

Callro filters unauthenticated robocalls, neighbor spoofing attacks, and Caribbean one-ring traps entirely on your Android device — with zero cloud contact uploading.

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