After considerable confusion, state regulators now say the demise of the 760 area code in North County will apply to cell phones, too.

To cope with steadily growing demand for new phone numbers, the California Public Utilities Commission on April 24 imposed a new area code -- 442 -- on consumers in North County.

The move, which came just nine years after the region was split from the 619 designation, was preceded by little opposition among local elected officials.

However, a Leucadia resident has launched an Internet-based effort to lobby regulators to reverse their decision.

And such opposition could gain steam as the hassles of changing phone numbers sink in for local cell phone users who have grown accustomed to moving about the country while keeping their numbers.

As it stands, cell phones are scheduled to switch along with landlines from 760 to 442 beginning Nov. 8, according to state and federal regulators.

Yet the inclusion of cell phones was apparently news last week to staff members of the California Public Utilities Commission, the regulatory agency that authorized the area code split.

On Friday, a commission spokeswoman told the North County Times that cell phones would not be affected. But she retracted that statement after being contacted by the North American Numbering Plan Administration, which handles phone numbers under a federal mandate.

Quirks of how cellular and Internet phone numbers are assigned have broken the once-automatic link between a number and geography, said Joe Cocke, senior area code relief planner for the western region of the numbering plan administration.

That means the geographical maps listing areas affected by the split are not necessarily accurate. The only certain way to know a number's fate is to look up its prefix in the "planning letter" issued by the group, Cocke said. If the prefix is listed, the number will change. If not listed, the number will not change.

The "planning letter" for the 760 split is available on the administration's Web site at www.tinyurl.com/4tdm4k. Affected numbers are also listed with this article.

Confusion abounds

The new 442 area code begins on Nov. 8 as an option. Until May 16, 2009, calls using both the old and new area code will be completed normally.

From then on, calls using the old area code will not be connected. A recorded message will tell callers to hang up and dial again with the 442 area code.

There's also a chance the area code split could be changed to keep North County within the 760 region.

That's the goal of Leucadia resident Scott Chatfield, who is leading a movement to make the commission change its decision. It has a Web site at www.keep760.org.

Simple enough? Not for Oceanside businessman David Churchill, who said he got differing accounts on the area code change from telephone directory companies and his own cellular provider, Verizon Wireless, earlier this month.

Churchill, who runs a real estate appraisal business, said he wants to keep his 760 area code cell phone number. He had great difficulty finding out if his number was in the new 442 area code.

"I called Verizon, and (the representative) asked me for my prefix, 518," Churchill said. "She said, no, that won't change."

However, Churchill said he found out his number would change after contacting Cocke. He referred Churchill to the planning letter, which listed his prefix as one that will change.

Churchill said the matter was urgent because he was placing advertisements in telephone directories, and needed to know which number to use.

The directories are to be delivered in August, well before the split is to take effect.

A second call to another Verizon Wireless representative was no more satisfactory, Churchill said.

"He said the change was pending," Churchill said. "He couldn't tell me whether or not my prefix was going to change."

Ken Muche, a Verizon Wireless spokesman, said cell phone numbers will be included in the area code split.

Churchill said he was incorrectly told by a telephone directory company, Yellow Book, that his cellular number would not change. But after calling back, he said, the company said the number would change.

"It all depends on whom you talk to," said Churchill, who decided to list both his old and new numbers.

Churchill said the company told him that adding a line to his ad giving the new number will cost him an extra $9 a month.

Geography not a guide

Verizon and other wireless carriers favored another option over the split: an "overlay" that would keep current numbers intact, and give the 442 area code to new numbers. The Public Utilities Commission rejected that alternative in favor of a geographic split.

However, a geographic split isn't the neat and tidy thing it used to be. Cell phone and pager numbers are by definition not tied to a geographical location the way traditional landline phones are, Cocke said.

And even landline numbers are mobile, if they operate through "voice over IP" Internet telephone technology.

Just as e-mails can be sent from anywhere a location is hooked up to the Internet, so can Internet telephone calls be made from any location with Internet access.

Businesses with Internet telephone service may get numbers with area codes far away from their physical location, to make it easier to do business with customers in that area.

This mixture of technologies can create some curious scenarios.

Both cellular and Internet phone numbers remain technically assigned by geography to the area code and the prefix.

And the prefix determines which numbers are assigned to a new area code, Cocke said.

So when a split occurs, all the cellular and Internet numbers in a prefix move along with the landline numbers.

Since cell phone customers usually have the choice of keeping their numbers when they move, some apparent exceptions to this rule can emerge.

A cell phone customer living in North County whose prefix is not on the 442 list will remain in the 760 area code.

Or, a customer could move out of North County and keep the 760 number. The customer could even live in another state.

But if the prefix is on the list, then the customer will get the 442 area code when the split occurs.

Gary Collins, of Temecula, kept his old area code for his cell phone in 2004 when Southwest Riverside County was given its own area code of 951.

Collins said the cell number originally belonged to a company he worked for. When he left the company, it agreed to let him keep the number. The number's prefix, 730, is not on that planning letter's list. It's assigned to Ontario, well out of the area designated for the 951 split.

Whatever the inconvenience an area code change causes, you won't pay extra for phone calls, Cocke said.

"The area code change will not cause the cost of a call to change," Cocke said. "Local calls will still remain local calls."

Contact staff writer Bradley J. Fikes at (760) 739-6641 or bfikes@nctimes.com.

760 SPLIT: Will your number change?

All telephone numbers with a 760 area code and a prefix listed below will change to the new 442 area code. Prefixes not listed below will remain in the 760 area code.

201, 204, 207, 208, 210, 212, 213, 214, 215, 216, 224, 225, 230, 231, 233, 236, 237, 239, 260, 268, 270, 271,274, 277, 283, 286, 290, 291,293, 294, 295, 297.

300, 304, 305, 310, 313, 315, 317, 330, 331, 334, 338, 385, 390.

400, 402, 405, 407, 410, 414, 415, 419, 420, 421, 429, 430, 431, 432, 433, 434, 435, 436, 438, 439, 440, 443, 444, 445, 448, 450, 451, 452, 453, 454, 456, 458, 465, 466, 467, 468, 470, 471, 472, 473, 476, 477, 479, 480, 481, 484, 487, 489, 492, 494, 496, 497, 498.

500, 503, 504, 505, 509, 510, 512, 516, 517, 518, 519, 520, 521, 522, 525, 526, 527, 528, 529, 532, 533, 535, 536, 539, 542, 543, 546, 547, 551, 557, 558, 560, 566, 571, 575, 576, 579, 580, 583, 585, 586, 591, 593, 594, 597, 598, 599.

602, 603, 607, 612, 613, 615, 621, 622, 630, 631, 632, 633, 634, 635, 637, 638, 639, 642, 643, 644, 645, 649, 650, 651, 652, 653, 654, 655, 658, 661, 666, 670, 672, 675, 681, 682, 683, 685, 687, 688, 689, 690, 692, 695, 696, 697.

703, 704, 705, 707, 708, 710, 712, 714, 715, 716, 717, 720, 721, 722, 723, 724, 725, 726, 727, 728, 729, 730, 731, 732, 734, 735, 736, 737, 738, 739, 740, 741, 742, 743, 744, 745, 746, 747, 748, 749, 750, 751, 752, 753, 754, 755, 757, 758, 759, 761, 763, 765, 767, 781, 782, 783, 787, 788, 789, 795, 796, 798.

801, 802, 803, 804, 805, 806, 807, 809, 814, 815, 818, 822, 823, 825, 826, 827, 828, 829, 839, 840, 842, 845, 846, 847, 850, 855, 857, 859, 860, 870, 871, 877, 884, 888, 889, 891, 892, 896,

901, 907, 908, 913, 916, 917, 918, 926, 929, 930, 931, 936, 940, 941, 942, 943, 944, 945, 966, 967, 975, 978, 986, 990, 994.

Source: North American Numbering Plan Administration.