A PUC decision on April 29 of this year to split off North County from the 760 area code and slap it with a 442 area code angered enough citizens in the area from Oceanside to Julian to "whipped up a website, mounted an enormous e-mail campaign, enlisted elected officials and petitioned a judge to order the PUC to reconsider the decision, while also lobbying the PUC on its own to give it a second look."

If the North County residents were forced to change to the 442 area code, then it would cost "at least $60 million for businesses to change signs and business cards."

The PUC decided to split the area code because the 760 area code is almost out of phone numbers. The 760 area code covers a large swath of California stretching from Lee Vining near Yosemite National Park all the way down the state’s eastern border and then west to Oceanside. The PUC states that they used up 3.5 million of the phone numbers available, with 4.36 million numbers available. This means that each area code has 7.86 million numbers in it.

San Diego City Beat learned from North American Numbering Plan Administrator (NANPA) that there were only 35 prefixes left to be assigned to the phone companies. That's 35 prefixes available, while 751 of them were already assigned, with most of the phone numbers still unused by the customers. NANPA thinks that the 760 area code will run out of numbers by fall of 2009.

Out of the 7.86 million numbers, each prefix holds 10,000 numbers, hence the four-digit number that comes after the three-digit prefix, so each area code has 786 prefixes. Why there isn't 1,000 area codes available for each area code is because 214 of them are reserved for other uses. A prefix cannot begin with a zero or a one, meaning that 200 numbers are eliminated (0 and 1 at the beginning of a phone number are used for special purposes). 555 is a fictious prefix used in entertainment so that's not available. 976 is for special fee services. 950 is for connecting to a different carrier. 700, 958, and 959 are for technical purposes and testing. 211 is for community services. 311 is for government services, non-emergency. 411 is for directory assistance. 511 is for traffic information or police non-emergency services. 611 is for telephone company (telco) customer service and repair. 711 is for TDD relay for the deaf. 811 is for underground public utility location. 911 is for emergency services. Therefore, each prefix has 7.86 million phone numbers for consumer and business use.

The 619 area code, however, will be running out of phone numbers to hand out by 2014. The residents in that area code fought off a proposed split of the area code about 10 years ago, but it may soon be necessary to have an overlay or a split.

Anyway, you get the idea of how many phone numbers we're dealing with for each prefix. This leads me to this question: Why not get ten times more phone numbers by adding another digit? We can have a five-digit suffix instead of a four-digit one like today and get ten times more phone numbers. Instead of 7.86 million phone numbers per area code, we could have 78.6 million phone numbers for consumer and business use. That's a whopping 70.74 million phone numbers that could be added for each area code simply by adding one digit! Problem with running out of phone numbers will be solved, in fact, some area codes could be combined.

How much does it cost us including the phone companies in the U.S. to switch to a five-digit phone suffix? I'm not sure how much it would cost, but the cost savings of having a prefix that lasts far longer would outweigh the costs of adding another digit to a phone suffix so that we could get an eight-digit phone number for local calls, or 11 digits for calling into another area code within the country. Add 1 at the beginning for long distance calling, and it would be a 12-digit phone number such as 1-800-555-12345. Initially it would cost money for everbody to get a new phone number, but another alternative is for existing businesses and consumers to keep the old four-digit suffix phone numbers while newer phone customers would get a phone number with a five-digit suffix. The older four-digit suffix customers could dial a "0" as the fifth suffix digit so that instead of 555-1234, they could dial 555-12340. Just add a "0" at the end of their old phone number and they're already with the new phone number.

So as for the old Tommy Tutone song, 867-5349, that number would be converted to 867-53490. The old Glenn Miller song PEnnsylvania 6-5000 would have to become PEnnsylvania 6-50000, or Pennsylvania six-five-ten-thousand.

Seven-digit local phone numbers are so 20th century. Why not eight digits at last?

Sources include SD City Beat Sep 17, 2008 and Wikipedia.