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 | 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.
988- National Suicide Prevention Lifeline. The United States Department of Health and Human Services' Substance Abuse and Mental Health Services Administration, in partnership with the Department of Veterans Affairs, administers the National Suicide Prevention Lifeline, which is a national network of approximately 170 local and state funded crisis centers.
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 Area Code
The 559 area code is expected to run out of available prefixes by September 2025. To address this, the CPUC has initiated the process to introduce a new area code into the area currently served by the 559 area code. This is aimed at providing additional prefixes and new telephone numbers for customers in the 559 area code. Pending approval by the CPUC, this new area code will be implemented through the overlay method.
On January 26, 2023, NANPA (North American Numbering Plan Administrator) submitted a request,A.23-01-012,to the CPUC on behalf of the telecommunications industry, seeking approval for the overlay in the 559 area code region to ensure the availability of additional numbering resources.
- 559 area code webcast
- 559 area code presentation
530 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
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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
I am a telecommunications expert with in-depth knowledge of the North American Numbering Plan (NANP) and the intricate details of telephone numbering systems. My expertise spans the management of the Public Switched Telephone Network in the United States, Canada, and select Caribbean countries, specifically under the North American Numbering Plan Administrator (NANPA).
Now, let's delve into the concepts mentioned in the provided article:
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North American Numbering Plan (NANP):
- Definition: The telephone numbering system managing the Public Switched Telephone Network in the U.S., Canada, and some Caribbean countries.
- Managed by: North American Numbering Plan Administrator (NANPA).
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Numbering Plan Areas (NPAs):
- Definition: Divisions within NANP identified by three-digit area codes.
- Format: Telephone numbers structured as NPA-NXX-XXXX.
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Area Codes:
- Definition: Three-digit codes identifying specific geographic areas within NANP.
- Example: California has 40 area codes, including 209, 530, 661, etc.
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Federal Communications Commission (FCC):
- Role: Exclusive jurisdiction over telephone numbering in the United States.
- Delegation: Specific authority delegated to state regulatory agencies.
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California Public Utilities Commission (CPUC):
- Role: Conducts area code relief and enforces number conservation in California.
- Authority: Granted by the FCC.
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Area Code Relief:
- Definition: Adding a new area code when three-digit prefixes are exhausted.
- Methods: Geographic split or overlay.
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N11 Codes:
- Examples: 211, 311, 411, 511, 611, 711, 811, 911, 988.
- Functions: Community information, non-emergency services, directory assistance, traffic information, customer service, relay service, call-before-you-dig, emergency services, National Suicide Prevention Lifeline.
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988 Dialing Code:
- Designation: 3-digit code for National Suicide Prevention Lifeline.
- FCC Order: All area codes with 988 prefix to change to 1+10-digit dialing.
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Area Code Changes in California:
- Examples: 559, 530, 213/323/738, 209/350, 707/369.
- Methods: Overlay method for 559, 530, and 213/323/738.
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Carrier Responsibilities:
- Surcharges: Interconnected voice over internet providers must collect and remit surcharges.
- Support: Surcharges support California universal service programs.
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Inquiries:
- Contact: Numbering policy and area code relief inquiries can be directed to Numbering_Help@cpuc.ca.gov.
Feel free to ask if you have any specific questions or if there are additional details you'd like to explore.