1-800-TOW-KARS. 1-800-FLOWERS. 1-800-PET-MEDS. 1-800-800-4CDW. You see phone numbers like this a lot. But where did those letters come from? Why are they on the phone in the first place?
Companies use letters in their phone numbers all the time to help you remember their numbers. But this wasn’t always done.
Not until recently did telephones contain sophisticated electronic parts like microprocessors. They didn’t have the plethora of other features cellphones have today like calendars, contact lists and apps to name only a few. Older phones were powered by the phone line itself and could only dial numbers and and connect callers to other people. An unanswered phone would ring until the caller hung up, even if the caller waited for 20 minutes or more. There were no features like voice-mail. If the phone was on a call another caller would get a busy signal. There was no call waiting. No call forwarding. No caller ID. There was no number preview – the call receiver had no clue who was calling until s/he picked it up.
The history of phone numbers and other interesting phone facts is the topic of this article. Depending on your age you may remember some or all of these interesting facts.
Single-digit phone numbers
In some areas very early on there were telephone numbers with only one digit. Of course that would only allow for a very small number of telephones. Pat Sajak, on his late night talk show in about 1990, told a joke about a really old telephone booth. “For a good time call 7” was written on the wall. As time passed and more and more telephones were used, longer numbers had to be employed.
Letters on the phone dial
There was concern that people would have difficulty remembering phone numbers when they became longer than four or five digits. So each digit from 2 to 9 was assigned three letters (see the photo accompanying this article). This used 24 of the 26 letters of the alphabet with Q and Z omitted. Today Q and Z are often assigned to numbers 7 (PQRS) and 9 (WXYZ) respectively.
When the 10-digit phone numbers we know today arrived, each number had an area code (3 digits), an exchange (3 digits) and a number (4 digits). The exchange consisted of two letters corresponding to the area where the exchange resided, and one digit. For example an exchange in Ingersoll would start with IN which translated into 46. Hunter could have HU7 as its exchange. A typical phone number in Ingersoll was IN7-1788 (467-1788). The purpose for the letters was to help people remember the number based on the location. Today with computerized phones there are contact lists so you don’t have to remember numbers. Many companies use the letters in a different way – using letters instead of numbers to spell one or more words, which makes it easy for people to remember their number.
‘Dialing’ a phone number
The term ‘dial’ came from the fact that you had to use the rotary dial to select the number to make the call (see the photo above).
When you picked up a rotary phone to make a call, a switch connected the phone electrically to the telephone company’s equipment. Inserting your finger into a number in the dial and turning it would ‘make’ one or more relay contacts, one ‘make’ for each number dialed. For example, if you dialed a two, the relay would make a relay connection twice. The equipment would see the number of contacts made and select the number accordingly.
Circuit- versus packet-switching
The rotary dialing method of connecting two telephones is called circuit-switching which means that once the number is dialed both telephones were physically connected by a wire. As long as those phones are connected the two parties can talk.
Newer equipment uses packet switching. This means a physical wire is not connected but the conversation is converted into a digital format, divided up into packets and sent through a network of interconnections. Each packet has a destination location embedded into the packet itself. The switching/routing equipment in the network looks at the destination of each packet and sends it through the network to the correct destination. Once the packets arrive at the destination they are re-assembled and converted back to analog. An analogy may be useful here – suppose your company made a large purchase of computers which consists of 250 boxes. This shipment requires three trucks. Each truck may travel a different route and arrive at a different time to the destination – the unloading dock of your company. Once all three trucks arrive the shipment can be put together again.
0 and 1 in the exchange middle position
Area codes used to always have either a 0 or a 1 in the middle position. The original area code for Washington state was 206. The 213 area code was one of the three original area codes created for California in 1947.
Conversely exchange numbers never had a 0 or a 1 in the middle position. This enabled telephone switching equipment to determine whether a local number or a long distance number was being dialed. Because of this standard you could dial a 1 and a local number (without dialing the area code) anywhere within a given area code because the equipment knew it was either a local or long distance call by the second digit of the number dialed.
In the late 1980s and early 1990s fax machines and computer bulletin boards along with homes with two phone lines necessitated more and more telephone numbers. Cellphones were barely available in the early to mid 1990s but as they became more and more popular they used up more and more numbers. All of this caused the need for more numbers.
In 1991 the rules were changed. Area codes could use any number in the middle position and exchanges could use 0 or 1 in the middle position. This required, however, that the area code be dialed for all long distance numbers whether the number was in the area code or not.
Now it is common to see area codes like 385 (a new area code in Utah) and exchanges like 302 (a newer exchange in Utah). People familiar with how numbers were assigned in the past tend to see those new numbers as odd.
In the movies and on television it is now common to use 555 as an exchange when telephone numbers are used. This exchange is reserved and is not used for valid numbers. In the past numbers were arbitrarily chosen in movies, on television and in other forms of media, and if that number happened to be a valid number the owner could receive a barrage of phone calls. You may remember in 1982 the song 867-5309/Jenny by Tommy Twotone. This caused a multitude of people to call that number and ask for Jenny.
With smartphones today we don’t even think twice about phone numbers. We don’t ‘dial’ them anymore. We just choose the number and hit send. It would be difficult for most people to even remember numbers because they call from their contact list. That is if they even call in the first place – they may text instead.