California has experienced a significant surge in demand for telephone numbers, leading to a rapid increase in area codes. This phenomenon, known as area code proliferation, is driven by factors such as competition in local phone services, the widespread use of technologies like fax machines, pagers, cell phones, and internet services, as well as California’s robust business growth and population expansion in the 1990s. This increased demand is further complicated by an outdated number allocation system from the 1940s, which was not designed for today’s competitive telecommunications market where multiple companies require number blocks.
Historically, a single phone company served a specific area, and new area codes were introduced as populations grew. California’s area codes steadily increased from just 3 in 1947 to 13 by 1992, remaining stable until 1997. However, in just three years, this number nearly doubled to 25 by the end of 1999. The Telecommunications Act of 1996 played a role in this expansion by fostering competition in the local telephone service market. As new competitive local phone companies entered the market, each required its own blocks of numbers, contributing to the area code proliferation.
In the traditional system, telecommunication companies received number blocks of 10,000 (prefixes) when needed. This system often led to inefficiency, as companies might receive far more numbers than they immediately required. For instance, a company with only 500 customers would receive the same 10,000-number block as one serving 9,500 customers. This practice of allocating numbers in large blocks created artificial demand and accelerated the need for new area codes. This allocation method, suitable for a time when a single company served each area, became inefficient with over 200 telecommunications companies in California needing numbers.
In essence, the escalating demand for numbers, regulatory changes, and an inefficient allocation system have collectively driven the rapid creation of new area codes throughout California. The state’s area codes have nearly doubled since 1997, and without proactive number conservation measures, projections indicated the potential for 22 more area codes by 2003. However, constantly creating new area codes is not a sustainable long-term solution as the number of companies needing dedicated number blocks continues to grow.
The History and Location of Area Code 831
Area code 831 serves as a prime example of area code proliferation in California. So, Where Is Area Code 831 located? Area code 831 covers the Central Coast region of California, encompassing cities and communities primarily within Monterey and Santa Cruz counties, and a small portion of San Benito County. Key cities within the 831 area code include Salinas, Monterey, Carmel-by-the-Sea, Santa Cruz, Watsonville, and Gilroy. This scenic region is known for its beautiful coastline, agricultural lands, and tourism.
The 831 area code was established in July 1998 as a split from the 408 area code. However, the history extends further back. Area code 408 itself was originally part of area code 415, one of California’s original three area codes created in 1947. Area code 415 initially covered a vast area of central California. Over time, the geographic area originally under area code 415 has been divided into five additional area codes: 209, 408, 510, 650, and 707, reflecting the dramatic population and technological growth of California.
Alt text: Map of California highlighting area code 831 location on the Central Coast, showing its geographic context within the state’s numbering plan.
Currently, the North American Numbering Plan Administrator (NANPA) has not determined that area code 831 is facing imminent number exhaustion. When area codes do approach exhaustion, the options for relief are typically geographic splits or overlays. An overlay involves introducing a new area code that covers the same geographic territory as the existing one. In an overlay scenario, both the new and old area codes require 1 + 10 digit dialing (1 plus the area code and the seven-digit number) for all calls within and between the area codes, as mandated by the CPUC and Federal Communications Commission (FCC). As of the time of the original article, the CPUC had not yet made a decision regarding an exhaust relief plan for area code 831.
The implementation of the first overlay and mandatory 1 + 10 digit dialing in the 310 area code (Los Angeles area) in 1999 faced significant public opposition. Due to these strong objections, the CPUC temporarily halted the 310 overlay and ten-digit dialing in September 1999. Subsequently, in December 1999, CPUC Decision 99-12-051 suspended all previously approved overlays. This decision also directed the CPUC’s Telecommunications Division (TD) staff to conduct a utilization study to assess the availability of unused numbers within area code 831. This study was intended to provide data-driven insights for future decisions regarding area code management.
Prefix Allocation and Number Management in Area Code 831
For area codes nearing number exhaustion, the CPUC established a lottery system to fairly allocate the remaining prefixes among phone companies when demand exceeds supply. However, area code 831 does not currently have a lottery system in place. Instead, companies in the 831 area code receive numbers directly from the Code Administrator.
For initial prefix requests, there are generally no restrictions, provided the company is authorized to offer telecommunications services in California. For growth prefixes (additional prefixes beyond the initial allocation), companies must meet specific criteria, including a 75% fill rate of their currently held numbers, demonstrating that they will exhaust their current supply within six months, and regularly reporting to the FCC.
Between January 1, 2000, and December 31, 2000, companies in area code 831 requested and received 56 prefixes. During the same period, as the CPUC worked with companies to reclaim excess prefixes, 12 prefixes were returned to NANPA, resulting in a net distribution of 44 prefixes. In the first eleven months of 2001, 27 prefixes were requested and granted, while 17 were returned, resulting in a net distribution of 10 prefixes. As of November 30, 2001, there were 458 prefixes available for assignment in area code 831.
CPUC Initiatives to Address Area Code Proliferation
Recognizing the considerable social and economic disruptions caused by frequent area code changes, the CPUC has proactively taken steps to address the numbering crisis. Responding to widespread public dissatisfaction with the increasing number of new area codes, the CPUC suspended all previously approved plans for new area codes starting in December 1999. Furthermore, in July 2000, the CPUC implemented number conservation measures, including the introduction of number pooling trials, fill rate requirements, and sequential numbering practices.
Number Pooling Initiatives
With FCC approval, the CPUC initiated number pooling in fourteen area codes to enhance the efficiency of phone number allocation. Number pooling was also mandated for an additional two area codes in early 2002, with national number pooling commencing in March 2002. The plan was to implement number pooling in three to four additional California area codes per quarter, with area code 831 tentatively scheduled to begin number pooling in fall 2002. The goal was to have number pooling implemented throughout California by spring 2003.
Number pooling allows telephone companies to receive numbers in smaller blocks of 1,000 instead of the traditional 10,000. This enables multiple providers to share prefixes, making more efficient use of this limited resource. Local Number Portability (LNP) technology makes this possible by allowing the network to support the assignment of smaller number blocks. The FCC mandated LNP to enable customers to keep their phone numbers when switching providers. This same technology is utilized for number pooling. Wireline carriers in the most populous 100 Metropolitan Statistical Areas (MSAs) in the US, including thirteen in California, were required to be LNP-capable by the end of 1998.
While LNP technology had been available for some time, cellular and PCS companies received an extension until November 2002 to become LNP-capable, and paging companies were permanently exempted from the LNP requirement. Consequently, initially, only wireline carriers could participate in number pooling. In area codes with number pooling, wireline carriers participate in pooling, while wireless carriers participate in the lottery system (or receive prefixes from the Code Administration if there is no lottery, as in the case of 831 at the time). In area codes with rationing but without pooling, all phone companies participate in the lottery.
The CPUC aggressively pursued the implementation of number pools. For area code 831, number pooling was tentatively scheduled for fall 2002. Once implemented, all wireline companies with numbers in area code 831 would be required to contribute 1,000-number blocks to the pooling administrator. While FCC rules only mandated number donation in rate centers within the top 100 MSAs, many companies had implemented LNP throughout their service territories. These companies could donate and receive thousand-blocks in all rate centers within an area code’s number pool, not just those in the top 100 MSAs. Under number pooling, all LNP-capable carriers receive numbers in blocks of 1,000 on an as-needed basis, without rationing. Wireless carriers would continue to receive numbers in blocks of 10,000 through the lottery or from the Code Administration.
Enhanced Number Inventory Management
While number pooling improved number distribution efficiency, it did not strongly incentivize companies to manage their existing number allocations effectively. Therefore, the CPUC mandated improved number inventory management through rules on fill rates and sequential numbering. In July 2000, CPUC Decision 00-07-052 extended number conservation measures initially adopted in the 310 area code to other California area codes. These measures included:
- Companies are required to return unused prefixes held for over six months to NANPA.
- An “imminent exhaust criterion” was established in lottery or pooling trial area codes. Companies requesting more numbers must demonstrate they will exhaust their current numbers within six months.
- Companies must meet a minimum 75% fill rate before requesting growth prefixes in rationing area codes or receiving thousand-blocks through number pooling. Numbers must be assigned sequentially within thousand-blocks, moving to the next block only after achieving a 75% fill rate in the previous one.
The TD anticipated that these policies would free up more numbers for pooling, lottery allocation, or direct company use. These measures, combined with number pooling, were already showing positive results. For example, the demand for growth prefixes in monthly lotteries significantly decreased after the CPUC extended the 75% fill rate and imminent exhaust rules to all area codes. Furthermore, the increasing return of excess prefixes to NANPA by companies in area code 831, as noted earlier, also indicated the effectiveness of CPUC’s number conservation policies.
CPUC Advocacy at the Federal Level
The FCC has exclusive jurisdiction over numbering in the United States. Therefore, the CPUC’s number conservation policies are subject to the FCC’s delegated authority to the states. Recognizing the severity of California’s numbering crisis, the CPUC actively petitioned the FCC for expanded authority. As a result, the FCC delegated authority to plan and implement area code changes and to implement number conservation measures.
Authority Regarding Pooling
On April 26, 1999, the CPUC petitioned the FCC for authority to implement number pooling trials and other conservation measures in California. On September 15, 1999, the FCC granted this petition, allowing mandatory number pooling trials, deployed sequentially across MSAs. While granting this authority, the FCC clarified that California’s authority could be superseded by future national measures from the FCC.
On March 31, 2000, the FCC released the first Numbering Resource Optimization Report and Order (first NRO Order). This order established rules for defining numbers, forecasting, tracking number usage, and conservation measures, including number pooling. The FCC adopted a nationwide system for allocating numbers in thousand-blocks where possible and announced plans for national thousand-block number pooling rollout.
Recognizing potential discrepancies between state-level trials and national standards, the FCC gave state commissions until September 1, 2000, to align their thousand-block number pooling trials with the national framework. One California-specific requirement, the 75% fill rate, differed from national standards. The CPUC requested a waiver to continue using this rule, citing its success in the 310 pooling trial. On August 31, 2000, the FCC granted the CPUC temporary authority to continue using its pooling rules until the FCC decided on the waiver petition’s merits or until December 31, 2000.
On December 29, 2000, the FCC issued its Second Report and Order on Number Resource Optimization (second NRO Order). The FCC ruled that the CPUC could continue using its utilization thresholds, subject to FCC-set parameters (California must adopt more stringent FCC thresholds if they exist). The FCC also declined to implement a transition period between cellular carrier LNP implementation and mandatory number pooling participation.
The first NRO Order prioritized thousand-block number pooling rollout in area codes within the largest 100 MSAs. The CPUC argued that this might limit the exploration of number pooling in other areas of California facing numbering crises but outside the top 100 MSAs. The CPUC advocated for FCC delegation of authority to states to order LNP deployment, which would enable pooling statewide.
Authority Regarding Technology-Specific Area Codes
State commissions are restricted by the FCC from creating area codes specifically for wireless services. On April 26, 1999, the CPUC also petitioned the FCC for authority to create service-specific or technology-specific area codes. In area code 831, 17 wireless carriers held 83 prefixes. Creating a separate area code for wireless companies could free up these prefixes in area code 831 for other uses, potentially extending the life of the existing area code. As of the original article, the FCC had not acted on this petition but requested further comments on technology-specific or non-geographic area codes in the second NRO Order.
On September 28, 2000, California enacted Senate Bill (SB) 1741, requiring the CPUC to request FCC authority for technology-specific area codes for wireless and data communications, and to allow 7-digit dialing within both the technology-specific area code and the original underlying area code(s). The CPUC was mandated to use this authority unless there was a specific reason not to. The legislation also prohibited the CPUC from implementing any authority that would impair number portability and from approving new area codes without a telephone utilization study and implementation of all reasonable number conservation measures. The CPUC’s April 1999 petition fulfilled the technology-specific area code request in SB 1741, and the utilization study addressed the study requirement.
Utilization Studies
Before considering another area code change for residents and businesses in area code 831, the CPUC recognized the need to assess the current usage and availability of telephone numbers. The CPUC required companies to provide usage data as of December 31, 2000. The TD contracted with NeuStar to collect and aggregate this data, which was submitted to TD in April 2001. The utilization study used specific definitions, detailed in Appendix A-1 of the original report.
This comprehensive utilization study and the CPUC’s proactive measures reflect a commitment to managing numbering resources effectively and minimizing the disruptive impact of area code proliferation on California residents and businesses, including those within area code 831.
