North American telephone area codes

North American phone numbers are in the format xxx-yyy-zzzz. In theory - there could be 10 billion combinations - enough for all the phone numbers in the world. But they say we are running out of area codes. You can’t have area codes (“xxx”) starting with 0 or 1, so that eliminates 2 billion numbers. You can’t have the first digit of “y” starting with 0 or 1 (or maybe you can now?). That eliminates 2 million more numbers within each area code. In any case, you should still have close to 8 million available numbers within an area code.

Why are we running out of numbers and area codes? Because phone numbers are usually allocated to service providers in groups of 10,000 (i.e. the “zzzz” part), and many of those 10,000 are never used. Wisconsin has seven area codes. With proper management, it should only need two - maybe three (for a population of 5.8 million, and likely a larger number than that of individual phone numbers).

So do we start managing things better, or just add an extra digit somewhere (as Australia did some years ago)?

This table shows the predicted dates when each area code is expected to be exhausted, and the changes over the last couple of years.

Far better to manage the numbers more efficiently. The number of computer system that will have issues with an extra number is considerable. Though thankfully many can handle it.

In the 1990s there was a major shakeup in area codes with many new ones added and old ones shrinking in coverage. In the Chicago suburbs where I grew up, 312 was the area code for all of Chicagoland in the 1980s, and by 2000 our area code had changed twice and 10-digit dialing had become mandatory even for local calls. 312 is now just the Loop and a few of the most immediate surrounding neighborhoods. The '90s saw houses move from one landline to having a second line for dial-up internet, car phones, and cell phones for some if not all family members. At the office, a shared main number with perhaps a couple of trunk lines became internal switchboards with enough direct-dial lines (real or virtual) for each person, and dedicated lines for fax machines, pagers, fire and security alarms.

Since that time however, those extra landlines for dial-up are no longer needed, car phones aren’t a thing, and having a cell phone more often than not means no land line. Fax machines are fading away, pagers took a while to go away but they’re finally mostly gone, and security systems are moving more towards internet connectivity rather than using the phone system (which may very well be the same company in a lot of cases, but they’re not using a phone number). Office phone systems seem to be relatively stagnant. It would appear that today the “phone numbers per person” is lower than it was in the early 2000s, even though it’s still higher than it was in the 1980s.

So like @What_Exit said, managing the allocations should be enough. The same is true for computer IP addresses. Large corporations and educational institutions got huge blocks of IPs in the early days, many of which are still completely unused. That’s been mostly mitigated by using just one or a small number of fixed IP addresses for the outside connection with a whole separate internal network addressing scheme (NAT). IPv6 with more numbers/letters helps too, though its adoption has been glacially slow.

I’ve been surprised over the past year or so that my crappy ISP, Cox, has begun adding more and more IPv6 routes. I’ve found when speedtesting to various locations around the world I now get more responses via IPv6 than only a few months ago.

Do we really even need area codes anymore?

It absolutely made sense back in the days when calls needed to be routed by switchboards, but now that everything is by computer, they don’t seem to serve much purpose.

Everyone I know who has moved in the past couple decades kept their phone number, living hundreds or thousands of miles away from where that area code is geographically located. Is there actually any efficiency to continuing to have area codes still?

It seems it would be easier to just open it up, and just start assigning arbitrary 10 digit codes to people who want a new phone number, than to try to manage the numbers geographically.

And now I have have “I’ve got phones in different area codes” stuck in my head.

xkcd on point:

Serious answer: We’re getting there. Mobile is out ahead of landline due to the infrastructure differences. But even now you can port a US landline anywhere else in the US. Switching from that to arbitrary 10-digit assignment is a relatively small step after that.

State and local regulation of local landline carriers is one of the larger remaining obstacles.

xkcd on point:

Serious answer: The allocation stuff has gotten a lot smarter than it was in the 1990s when the sky was announced to be falling imminently. And as you say, some aspects of number consumption have actually gone down. But we continue to need new NPAs and will for the foreseeable future.

Australia /also/ changed the management at that time. Numbers became partly portable, and only roughly locational. Areas were consolidated, freeing up assignment. Which was irritating, because phone charges could no longer be accurately determined from phone numbers, and because you couldn’t tell if you were speaking to a local business or someone an hour or two away.

And now, with VOIP entirely replacing the national telephone system, numbers are fully portable and don’t say anything about location at all.

I agree with what you’re saying except for this part. It’s a wash in a single person household but from a “phone number” perspective our household has quadrupled. Everyone now has their own phone number.

Even if I got rid of our landline ( which I have only because of bundling- getting rid of it will raise my bill), my husband and I still have four cellphone numbers between us ( we each have a personal one and one for work*) while in the 90s and early 2000s we had a single landline- no second or third line for a fax machine, internet service, alarm system or anything else. Before our kids moved out, we had six cell phone numbers and that landline between the four of us.

  • I know lots of people have a single cell for both work and personal use. We both have reasons not to do that.

I noted in my post that households may still have more numbers than before because of at least one cell phone per person, but the number of households retaining a landline when they also have cell phones has crashed in the last 10-15 years. So yes, 1 household of 4 people = 4+ cell numbers is higher than having just 1 landline, but it’s still lower than 4+ cell numbers AND a landline/fax line/pager/dial-up line.

When I was working, my boss would cover other departments on weekends, and he’d carry an extra phone or two to keep in touch. I would razz him, saying, “Only drug dealers carry more than one phone.”

I don’t know if it was national or just local (I think we were late to the party), but in the 60’s all local numbers went from six digits to seven. So our home number went from 55- to 595-. I think adding 9 in the middle was enough for all 808 phone numbers, since I remember just adding the 9 when calling someone.

I don’t know if it’s still true, but the blocks of prefixes for landlines were restricted to the landline companies, taking them out of the available pool for cell phones.

Area codes used to have a 0 or 1 as the second digit. When they dropped that requirement, it opened up many more numbers.

I think the U.S. is one of the few countries that decided to assign numbers to cell phones according to the locality. In Switzerland, and many other countries, cell phones got their own area code (which is Switzerland is called the national destination code).

So If I see a number which starts with 74-79, I know it’s a cell phone calling me.

So, except for country codes, I support random numbers.

And the only reason I want country codes to remain is so that I can block numbers calling from Ukraine, India, U.K., etc. Because those calls are always someone wanting to talk to me about Windows.

It certainly did.

But at the expense of having to introduce a new area code to get to those new numbers.

Which triggers all the attendant consumer confusion about local vs long distance pricing, the two kinds of long distance, do I dial 7 digits, 10 digits, or “1” + 10 digits?, What if I get that wrong?, etc, etc.

Plus when a split occurred, anyone who was in the geographical area designated for the new area code had to learn a new number (or at least first 3 digits thereof), all their callers had to be told about the new number. New phone books, both white and yellow had to be published. Every affected business had to get new business cards, advertising materials, brochures, stationery, invoice forms, etc.

All that was a huge obstacle to area code splitting in the 60s-90s. And made it a multi-year (often a full decade) effort from when the decision was made until they could actually first begin handing out the same trailing 7 digits in both the new and old area code. For the whole transition time it was 100% pain, zero% gain. Both for the public and for the phone cos.

Later when the infrastructure software had improved enough that they could do “overlay” area codes that meant nobody was forced to change their existing number. But all the user education problems remained.

Nowadays when most Americans live in an overlaying 10-digit dialing area, and most folks don’t know or care what “long distance” used to mean, the obstacles are much smaller. But still not zero.

What makes you think, even given a number ID that is real and not fake, that a number not from Ukraine, India, U.K., etc. is not in fact being used by someone in the Ukraine, India, UK, etc.?

Most of my spam calls now come from an adjacent number now. If my number was 647-387-5125, the call appears to come from 647-387-8382 for example. There is still an ingrained “that must be a neighbour, I better pick up.”

Same here. About half the spam calls I get are from some crazy looking number, but the other half have a local area code and often even a local exchange.

Spoofing is a thing. I got a bunch of phone calls one day that were listed as having come from my local electric company saying that they were going to come out and turn off my power if I didn’t go out and get them some Amazon gift cards.

I also had my personal number spoofed once, and had dozens of angry calls from people calling me to demand to know why I called them.

I’ve had spammers spoof my number. That was an odd one.