Area Codes and Numbering (2024)

The North American Numbering Plan (NANP) is the telephone numbering system within which the Public Switched Telephone Network is managed in the United States, Canada, and some Caribbean countries by the North American Numbering Plan Administrator (NANPA). The NANP is divided into smaller Numbering Plan Areas that are each identified by a three-digit code, commonly known as an area code. Telephone numbers in the NANP are structured in the format NPA-NXX-XXXX, in which

NPA is the 3-digit area code that identifies a specific geographic area;

NXX is the 3-digit prefix that identifies a specific central office within an area code; and

XXXX is the 4-digit line number that identifies a specific line within a central office.

The Federal Communications Commission (FCC) has exclusive jurisdiction over telephone numbering in the United States but has delegated specific authority to state regulatory agencies. Tasked with the authority granted by the FCC, the CPUC conducts area code relief and enforces number conservation in California in accordance with Public Utilities Code Section 7930-7943.

California currently has 40 area codes. A new area code is added to a geographic area when there are no more three-digit prefixes available in the existing area code. Area codes are added in the form of a geographic split or an overlay. California has added fourteen area codes using the overlay method since 2006.

California Area Codes

209/350*	530/837*	661	831
213/323/738*	559/357*	707/369*	909/840*
310/424*	562	714/657*	916/279*
408/669*	619/858*	760/442*	925
415/628*	626	805/820*	949
510/341*	650	818/747*	951

*Overlay

N11 Codes

211- Community information and referral services.211 service is provided by local community-based or government organizations that are authorized by the CPUC to use the 211 code to provide information and referrals to health and human services.

311- Non-emergency governmental services. 311 service is administered by municipal governments.

411 - Local Directory Assistance. 411 directory assistance is provided by individual telecommunications service providers or independent providers.

511- Traffic and Transportation information. The California Highway Patrol, California Department of Transportation, and local transportation agencies oversee 511 operations.

611 - General Customer Service. 611 service is provided by individual telecommunications service providers.

711- Telecommunications Relay Service for the speech and hearing impaired. In California, 711 Relay service is provided through Hamilton Relay.

811- Call-before-you-dig phone number for access to location of buried utilities. Underground Service Alert, a nonprofit organization, manages 811 calls and operates two call centers: USA North 811 for northern California and Dig Alert for southern California.

911 - Emergency services. The California Office of Emergency Services and local public safety agencies oversee 911 emergency service operations.

Information for Consumers

9-8-8 Dialing Code

On July 16, 2020, the FCC designated 988 as the 3-digit code for the National Suicide Prevention Lifeline (FCC 20-100), and ordered all area codes that have the 988 prefix in use and 7-digit dialing to change to 1+10-digit dialing to avoid problems routing calls dialed with the 9-8-8 3-digit code. In California, the 209, 530, 562, 626, 650, 707, 925, 949, and 951 area codes are impacted by this FCC order.

559/357 Area Code

The 559 area code is expected to run out of available prefixes by September 2025. On December 14, 2023, the CPUC approved an overlay and a new area code inDecision 23-12-012to provide additional numbering resources in the geographic region served by the 559 area code. The new area code to overlay the 559 area code is the 357 area code.

559 area code webcast

559 area code presentation

530/837 Area Code

The 530 area code is running out of available prefixes, and it's expected to be exhausted by September 2025. To address this, on June 8, 2023, the CPUC approved an overlay plan, as outlined in Decision 23-06-007, which involves introducing a new area code, 837, to supplement the existing 530 area code.

530 area code webcast
530 area code presentation

213/323/738 Area Code

The213/323area code is projected to be depleted of available prefixes by June 2025. On March 16, 2023, the CPUC approved an overlay and a new area code inDecision 23-03-006to provide additional numbering resources in the geographic region served by the 213/323 area codes. The new area code to overlay the 213/323 area code is the 738 area code.

213/323 area code webcast

213/323 area code presentation

209/350 Area Code

On November 28, 2022, the 350 area code was put in service and was overlaid onto the existing 209 area code.

707/369 Area Code

On February 1, 2023, the new 369 area code was put in service and was overlaid onto the existing 707 area code.

Information for Carriers

Interconnected voice over internet providers obtaining numbering resources in California must collect and remit surcharges in support of California universal service programs

Process for carriers requesting safety valve relief

Contact

For inquiries related to numbering policy and area code relief, please direct your questions to staff atNumbering_Help@cpuc.ca.gov

FAQs

How many area code combinations are possible? ›

The Area Code

These numbers represent a specific geographic area in North America. Each area code can support up to 792 combinations of the first three digits of a telephone number (known as an exchange code) and when these combinations are depleted, the area code is said to be exhausted.

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What are the first 3 numbers after the area code called? ›

There are 792 area codes. A prefix is the three digits of your telephone number that follow the area code. A prefix can begin with any number other than 0 or 1 and cannot end with 11 (as in 911 or 411 – as these are reserved for special uses).

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How many 7 digit numbers are possible in a single area code? ›

= 8,000,000. Therefore, according to the condition that the first digit cannot be either 1 or 0, we can have 8,000,000 possible ways of creating a seven-digit area code.

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How do you write an area code and phone number? ›

A: The phone number format in the USA consists of a three-digit area code, followed by a three-digit central office code, and finally a four-digit line number. The format typically appears as (XXX) XXX-XXXX.

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What are the odds of guessing a 7-digit code? ›

What are the odds of guessing a 7-digit number? There are 9*10*10*10*10*10*10 = 9,000,000 7-digit numbers. Therefore, the odds of guessing any one 7-digit number is 1 in 9,000,000. Good luck!

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Will we run out of area codes? ›

So what's going to happen when we eventually run out of area codes? There are currently a total of 335 area codes, with 18 of them being non-geographic. An analysis of the North American Numbering Plan estimates that the current structure is good until around 2049. After that, some changes are going to be needed.

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What does 00 mean in a phone number? ›

When you call a number in a different country you must replace the first zero from the area code with the international call prefix and the country code. The international call prefix is normally 00 (zero zero) or + (plus).

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How many area codes were possible before 1995? ›

1. How many area codes were possible before 1995? 8 [2-9] • 1 • 9 [1-9] = 72 possible area codes for N0Z and 8 [2-9] • 1 • 8 [2-9] = 64 possible area codes for N1Z —a total of 136. There are, in fact, a few other restrictions that reduce the number of available area codes to 681.

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What is the numbering plan area code? ›

Each NPA is identified by one or more numbering plan area codes (NPA codes, or area codes), consisting of three digits that are prefixed to each local telephone number having seven digits. A numbering plan area with multiple area codes is called an overlay. Area codes are also assigned for non-geographic purposes.

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Can two people have the same number? ›

In general, it is not possible for two people to have the same phone number. The reason for this is that each phone number is a unique identifier, and it is used to route calls and text messages to the correct phone.

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Can phone number start with 0? ›

Using 0 or 1 as the first digit of an area code or central office code is invalid, as is a 9 as the middle digit of an area code; these are trunk prefixes or reserved for North American Numbering Plan expansion.

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How many possible combinations of 10 numbers are there? ›

Since we have been told to find a combination of 10 numbers, n = 10. our r will vary from 1 to 10 as this are the possible combinations of 10 numbers and then we will have to add all these. Hence there are total 1023 combinations possible using 10 numbers. So, the correct answer is “ 1023”.

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Who has phone number 1? ›

The entities that are within the North American Numbering Plan – the United States and its possessions, Canada, Bermuda, and several Caribbean nations — share the international "country" code 1, with each state (or parts of states), province, territory, or island nation given its own three-digit "area code".

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Which country number starts with 0? ›

No country codes begin with '0' at this time, although such assignments may now be possible, following ITU's Time 'T' of 31 December 1996 in which international number lengths were expanded, and the possibility of zone 0 country codes established. Includes Canada, Caribbean countries, USA and its various territories.

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What is the proper format for a phone number? ›

U.S. and Canada. Since the U.S. and Canada both use the North American Numbering Plan, the commonly accepted formatting of phone numbers is (NPA) NXX-XXXX, NPA-NXX-XXXX or 1-NPA-NXX-XXXX. The 'NPA' is the area code, 'NXX' is the central office code, and 'XXXX' is the subscriber number personal to each phone.

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How many 3 digit area codes can be made? ›

How many 3-digit codes are possible if each digit is chosen from 0 through 9, and no digits are repeated. P(10,3)=10⋅9⋅8=720 . Hence, there are 720 possible 3-digit codes. I hope that this was helpful.

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Are we going to run out of phone numbers? ›

While there are billions of potential digit combinations, it's not an infinite number. Eventually, it's very possible we'll have used up every available phone number. Most people are familiar with the modern 10-digit U.S. phone number with an area code. But that's actually a fairly recent invention.

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How many 4 digit PIN combinations exist? ›

There are 10 possible numbers for the first digit, and then you can't use that number again, so 9 for the second, and using the same logic, 8 for the third and 7 for the fourth. That means there's 10×9×8×7=5040 combinations.

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How many numbers can fit in an area code? ›

An area code (technically called a Numbering Plan Area Code, NPA Code,) serves a geographic area and consists of 792 available prefixes, each consisting of 10,000 numbers. A prefix (NXX) is the three-digit number that is between the area code and the 4-digit line number.