1. 415 Background January 16-17, 2013 Katherine Morehouse California Public Utilities Commission

2. California Public Utilities Commission (CPUC) Role Federal Communications Commission (FCC) holds responsibility on numbering issues Area code relief delegated to states CPUC performs delegated responsibilties and determines method of introducing new area code Numbering Administration is performed by the FCC. The FCC’s role in numbering administration is referred to as the North American Numbering Plan Administration or Administrator (NANPA). NANPA tracks number usage, receives numbering reports from the service providers, provides forecasts on the life of area codes and develops alternatives for new area code introduction.

3. History 415 created in 1947 as one of the first area codes in California 1959 - 408 and 707 area codes split off from 415. 1991- 510 area code split off 1997 – 650 area code split off 1999, 628 overlay ordered for 415, which was suspended when CPUC implemented number conservation.

4. 415 Utilization Facts Utilization Comparison Available numbers includes only numbers from assigned prefixes. Prefixes and blocks not assigned are not included. National results are shown from December 2009 because that is the most recent report available. Assigned Assigned Percentage Intermediate, Reserved, Aging and Administrative Percentage Available Available Percentage 415 as of 6/30/12 424187550.35.3373736644.3 California as of 6/30/12 88,458,14860848,612,24733 USA as of 12/31/09 672,472,00047.96.5639,730,00045.6

5. 415 Assigned Numbers by Line of Business and by Rate Center Belvedere Corte Madera IgnacioInvernessMill ValleyNicasioPoint Reyes San RafaelSausalito San Francisco Central San Francisco Juniper San Francisco Montrose- Evergreen Stinson- Bolinas Wireline 36,331 37,988 59,169 23,776 53,627 16,086 70,897 34,552 237,250 56,622 1,677,872 216,364 206,417 19,622 Paging and Messaging 19 2 3,694 21,592 13,574 9 Wireless Telephony 20,425 3,493 1,100 4,677 1,600 46,189 131,160 17,343 1,078,615 45,783 106,027

6. Telephone Number Structure Telephone numbers are made up of area codes, prefixes and line numbers Line numbers are assigned to individual telephone services. Prefixes, also called central office codes, are assigned to groups of 10,000 numbers. Area codes are the first three digits in the telephone number. Area codes are assigned to specific geographies within the United States. Area codePrefixLine Number 4155551000

7. Number Limitations Area codes are geographically specific Each area code is divided into local serving areas called rate centers There are fourteen rate centers in the 415 area code. They are Belvedere, Corte Madera, Ignacio, Inverness, Mill Valley, Nicasio, Point Reyes, Point Reyes, San Rafael, Sausalito, San Francisco Central, San Francisco Juniper, San Francisco Montrose-Evergreen, and Stinson-Bolinas. Every prefix is assigned to a specific rate center and may only be used for telephone services in that rate center.

8. Service Provider Number Inventory Every service provider is entitled to numbers to assign to their end users. Numbers are assigned in blocks of 1000. There are ten blocks in each prefix or code.

9. Prefix Availability Drives New Area Code New area codes are required when the available supply of area code-prefix combinations have been assigned. Numerically there are distinct 1000 area code-prefix combinations, but only 800 are usable because prefixes can’t begin with a zero or one. Out of the 800 usable prefixes, eighteen are unassignable because they are special use prefixes (2- 1-1, 4-1-1, 9-1-1 and others). That leaves 782 prefixes available. Numbers assigned to customers is the greatest reason prefixes are assigned but the number of service providers in a local area also influences prefix assignments.

10. Relationship between Assigned Numbers, Number of Service Providers and Number of Prefixes

11. Each prefix is assigned to a rate center from the available inventory. Once assigned. Numbers from that prefix are not available for assignment to end users in another rate center. Mill Valley 17 Available 415 prefixes as of 7/1/2012 Belvedere 10 Ignacio 12 Nicasio 5 Sausalito 15 SNFC Central 448 SNFC- Mt-Ev 52 Stinson Beach- Bolinas 6 72 unassigned Corte Madera 11 415 rate centers and assigned prefixes Novato 18 Point Reyes 7 San Rafael 60 SF Juniper 48

12. 415 Assignment History 2007 = 4 prefixes 2008 = 2 prefixes 2009 = 3 prefixes 2010 = 10 prefixes 2011 = 21 prefixes 2012 = 21 prefixes

13. Prefixes Control Area Codes A new area code is necessary because there are only 61 more prefixes available for assignment A new area code will supply the people of San Francisco and Marin with 784 new prefixes for the addition of more service providers and more services.