How did Utah get its 801 area code? Why extras? And will others come?


801 is an identity.

Right now, you can buy all kinds of 801-branded gear: t-shirts, hoodies, bumper stickers, phone cases, hats, and more. Companies from 801 Accounting to 801 Web Design have chosen the number to represent their businesses. Uinta Brewing’s pilsner 801 is one of the best-selling beers in the state. This is all because many, but not all, Wasatch Front residents have phone numbers that begin with 801, and in some way all three of these numbers are tied to their home.

So I decided to look at area codes as a phenomenon. How did Utah end up with area code 801 in the first place? Why does Utah now have three area codes, including 385 and 435? Couldn’t they just fit all of Utah’s 3.3 million people into one code? And what is the future of Utah area codes? Could we add another soon?

The history of the area code

In the 1940s, AT&T realized there was a problem. It sat atop an empire of most telephones in North America, but they all came from these local and regional organizing groups, which meant everyone had their own dialing schemes. Human telephone operators were a necessity for long distance calls, both technically and logistically.

In particular, most American cities had an automatic central switch with a capacity of 10,000 numbers. In cities with more than 10,000 lines, customers dialed two letters — yes, letters — to indicate the switch they wanted to reach, then the five numbers of their desired answering machine. For example, the Salt Lake Tribune’s phone number at the time was EM-31511.

AT&T wanted to make the unification of these regional numbering schemes possible. The obvious answer was to add more digits in front of existing customer numbers when people wanted to dial outside their familiar local area; these were called area codes. AT&T also included 20 North American countries in the numbering plan, which was later reasonably called the North American Numbering Plan, or NANP. (Mexico and a few other small North American countries do not participate in the NANP.)

At first, only human operators knew about area codes, as a sort of primary solution to the dialing problem. The first consumer-dial long distance call was in 1951, and the practice spread throughout the 1950s to the point that direct dialing was standard by the early 1960s.

When first introduced there were 86 area codes – required by a combination of both population and amount of numbering systems at the time. Naturally, population growth over time has forced the introduction of new area codes, and there are now 447 assigned area codes in the NANP.

Why 801?

So how did we get to good old 801 here in Utah?

As AT&T administrators considered how to create the system, they first considered the technical aspect. In particular, how do you ensure that area codes are recognized as such and not part of a normal local number? Well, no two-letter telephone local switch office includes a zero or a 1. So they decided that every initial area code should include those digits in the area code of the second number to make sure it doesn’t wouldn’t be confused with a switching office. The second number 1s were assigned to states that were split, the second zeros were assigned to states with a single area code.

They then considered efficiency. They noted that it would be more efficient to keep the first and third numbers as low as possible for as many people as possible. People still used rotary phones to dial, and 8 and 9 took longer to dial than 2 and 3. Therefore, it made sense to give higher density cities, like New York, area codes lower digits like 212.

They also thought it might help people remember area codes if grouped geographically. This was the map offered when administrators first established the numbers in early 1947:

Bell Labs internal history document “Bell Labs, Memorandum 40979” ( -years/page/n10/mode/1up)

Ultimately, however, this proposal was rejected. Why? Well, for two reasons. First, a system like this might actually increase dialing errors, because people on the border of an area code district might not easily remember, for example, the difference between 212 and 213. More importantly, it was not as flexible for new growth. What if California’s population exploded and the state needed dozens of area codes fast? Area codes with a 5 at the beginning would be exhausted.

So, in the end, officials distributed them without really caring about geography. Utah rolled 801, a number with a large initial number but a small third number.

Original distribution of area codes. Note how efforts have been made to make area code digits take as little time as possible to dial. (

Why did Utah have to expand from 801?

It always bothered me. Why do we need more area codes than 801, anyway? With seven digits at the end, there should be room for 9,999,999 numbers in each area code, right? That’s far more than Utah’s 3.3 million people.

There are three main reasons for this.

• First, there are not 9,999,999 numbers available. Zeros and 1s are not allowed in the first digit of a seven-digit phone number. And numbers 211 to 911 are reserved for services, and numbers 555-0100 to 555-0199 are reserved for fictitious numbers. In the end, each area code has 7,919,900 numbers available.

• Second, there are more numbers than people. Businesses have phone numbers. Some people still have home phone lines, fax machines, even pagers with their own number.

• Third, we assign phone numbers quite inefficiently. Historically, local telephone companies handled blocks of 10,000 numbers at a time, all with the same three-digit prefix. They would assign an entire prefix to a large company and call it good whether that company wanted 2,000 numbers or 8,000. This became messy and unnecessary, so in 2002 the Federal Communications Commission said telephone companies should distribute blocks of 1,000 numbers, with the same four-digit prefix instead. This smaller block process helps but still results in a decent amount of waste.

The FCC’s most recent report on the matter, using 2019 data, showed that 69% of 801 area code numbers have been assigned. According to this report, traditional landline telephone companies are sitting on a whopping 1,593,000 numbers in the 801 area code, while mobile operators have 110,000 unassigned numbers. However, even if you were to distribute them all, the number of unassigned numbers in 801 still does not meet the needs of the state – hence the 435 and 385 area codes.

Why 385 and 435?

In the 1990s, the adoption of fax machines, pagers, etc. forced NANP administrators to rapidly expand beyond the “zero or 1 in the second digit” rule. The first area codes outside of this rule were assigned in 1995.

In 1996, it was clear that Utah would soon get a second area code. There are two methods of area code expansion: divide separates the geographical boundaries of a postal code into two, while the cover places a second area code within the same boundaries as the first. However, in 1997 the overlay method had not yet been used, so NANP administrators split Utah in two: Salt Lake, Davis, Morgan, Utah, and Weber counties would all remain on 801 , and the rest of the state would become the 435. .

Why 435? Well, state civil service officials initially requested the available area code 724 – acknowledging the July 24 holiday in Utah. But the 801-724-XXXX block of numbers was already assigned to Orem’s phones, and NANP administrators didn’t want to confuse the public about which 801 areas could dial seven digits, or the systems that would interpret those digits. Instead, the unassigned 435 was used.

“For us, area codes are buckets of digits,” an NANP administration spokesperson said when asked about the 435 selection. do.”

The 385 area code became necessary in 2009 but, by then, the overlay had become commonplace, so the NANP administrators did it. It was also assigned in a boring, unromantic and practical way.

The growth in numbers has slowed considerably, thanks to the reduction in home telephones, fax machines, pagers, etc. Area codes 801 and 385 should currently get us through at least 2032, while 435 should suffice until at least 2041.

Andy Larsen is a data columnist for The Salt Lake Tribune. You can reach him at [email protected].

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