A renewed request by phone companies to create a second area code in the 310 area prompted a letter, sent Monday, arguing against the change from three lawmakers to the state Public Utilities Commission.
The proposal would require people in the 310 area to use 10-digit dialing, according to the letter from Assemblyman Mike Gordon (D-El Segundo), Rep. Jane Harman (D-Venice) and county Supervisor Don Knabe.
The letter strongly opposes a petition filed Wednesday by six phone carriers to assign a 424 area code to new customers.
SBC California, Verizon and five wireless carriers say they are running out of numbers in the 310 calling zone, which stretches from Malibu to San Pedro.
Existing telephone numbers would be unaffected by any changes.
"Not only is such a system bad for consumers, it would also set a bad precedent for area code management in California," says the letter to commission President Michael Peevey.
Leon Bloomfield, an Oakland attorney who filed the petition for the carriers, declined to comment.
The proposal for a new calling prefix in the 310 area code has existed in various forms since 1999, said Janelle Beland, Gordon's legislative director.
Beland said that as many as six area codes in California could face similar battles by 2008.
"Here we are six years later and we still haven't run out of numbers," she said.
According to the letter, the system for evaluating how many numbers are available is "rife with inconsistency and manipulation" by phone carriers. Companies tend to hoard "vanity numbers" and blocks of sequential numbers, creating a false sense of shortage, Beland said.
In 2003, the commission determined that a split of the 310 area code was not warranted, Gordon's office said.
He recently introduced legislation, Assembly Bill 1380, to impose rules for determining number inventory and requiring that carriers return surplus numbers to a number pool.
Joining SBC California and Verizon in the petition are Cingular Wireless, Nextel of California, Sprint, T-Mobile and Verizon Wireless.