SAN JOSE (CBS SF) – A decision made by the California Public Utilities Commission Thursday means that residents and businesses in the South Bay will be spared from having to change their phone numbers when an overlay area code is introduced in the coming year.

Customer demand for new numbers has depleted the number of available phone numbers that use the 408 area code, which is predominantly in Santa Clara County as well as in neighboring cities and some unincorporated portions of Alameda and Santa Cruz Counties. The overlay method was approved in May by the Santa Clara County Board of Supervisors.

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Last December, the CPUC began working with the North American Numbering Plan Administrator, or NANPA, an international numbering plan for the U.S., Canada and several Caribbean countries. Both organizations met with telephone service providers to discuss the best way to implement a new area

Rather than split the area code, which would migrate some existing phone numbers from the 408 area code to the proposed 669 area code, the CPUC approved an overlay that will add the 669 area code to the same geographic region as the 408 area code.

Phone numbers with the 669 area code will begin being issued in November 2012. According to the CPUC, most but not all new numbers assigned in the overlay will have the new area code.

Beginning in April, customers calling any number in the 408 area code will have to dial the area code plus the seven-digit phone number. Calls will still go through if customers fail to do so, at least until Oct. 20, 2012, when the grace period for seven-digit dialing ends, according to the CPUC.

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Prior to making its decision, the CPUC held four public meetings in San Jose, Los Gatos and Morgan Hill in March to gather feedback on the topic from the public.

According to the CPUC, by July, comments and other input from the public showed that five times as many people favored an overlay as those who supported a split.

Telephone carriers strongly favored the overlay, the CPUC said, because it is less disruptive to customers than implementing a split area code.

CPUC Commissioner Timothy Alan Simon said in a statement Thursday that he has consistently supported the implementation of overlays over splits, which can be expensive for businesses forced into new phone numbers.

“I favor approaches that lower costs for small businesses in California,” Simon said. “Small business innovation and job creation are what make America great.”

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