I was at UCSD in the late 1970s, and lived in the dorms for most of that period. Every phone number on campus had the prefix 452-, whether it was in a professor’s or adviser’s office, or the bookstore, or your friend’s suite two floors down, etc. To call anyone on campus we needed to dial only the last four digits, in much the same way that we used to dial only the last seven digits if calling someone in the same area code.
Was this generally a thing outside of specialized and separate communities like big companies and university campuses? When I was growing up, we had the prefix 275-. Should I have been able to call another 275- number by dialing just the last four digits?
I started using phones in the 60s and never heard of just dialing 4 numbers. But I believe before that they had exchange numbers that you put in two letters for the exchange and then 3 or 4 numbers for the persons line in that exchange. I believe an exchange may have been a physical local operator in the area you were calling.
The long-running joke on Hee Haw was to call BR549 if you had questions. Suggesting that only rural hicks still used exchanges.
This is typical of any large organisation in the days of wired phones. My university was the same. We had our own PABX, (The A simply means it was an automatic private exchange - so no operators). Usefully towards the end of the era we used much the same Erricsson exchange equipment as the phone carrier, and the entire thing was connected to the outside world by a fibre. Actually there was more than one frame, and remote campuses were tied into the same system over fibre. Before then there were a fixed number of outgoing wired lines to the telco, which was why at peak times it was possible to be unable to make an outgoing call. Our department’s modem pool sat on the same PABX, and we had to sign in blood that we would only call into it after hours, so as not to hog the lines.
Westport MA allowed 4 digit dialing within town until 1991. They had to upgrade after the town got clobbered by Hurricane Bob. Long time residents were furious they had to start dialing 7 digits to call their neighbors.
That’s what I grew up with as well. Only four digits needed to call anyone in our town. Seven digits were used for long distance in our province, which only had one area code. The switch to seven digits locally occurred late in the 70s, I think.
Where I grew up in the 1970s, our town had two prefixes that had the same two digits at the beginning [XYA-#### and XYB-####]. We could call anyone in town with five digit dialing [A-#### or B-####].
Our local independent phone company did a major upgrade in the early 1960s, running new phone lines everywhere, which replaced the single wire which was strung mostly along power poles to each house. (Yes, we still had hand-cranked phones; each residence had a different ring pattern on the party line, and there was a human operator that we utilized to call somebody who wasn’t on your party line, as well as long distance.) The upgrade was to dial telephones, and the towns that it served had different prefixes. We could call anybody in our town with 4 digits, and anybody in the other town with 5 digits, similar to what @BurglarGenie described.
Around 1980, the upgrade occurred that made those dialing patterns obsolete. I no longer lived there, but everybody, including my parents, got new telephone numbers. Pissed off a lot of people.
The small town we lived in when I was little had 4 digit dialing. (I still remember the number.) There was a 3 digit (or 2 letter-one digit) prefix if you were calling from somewhere else in the county. I don’t recall what the deal was with calling from in town to another town.
Note that this was independent of area codes. Back then it was all operator assisted for long distance. Person-to-person, station-to-station, collect were among the options.
At some of the Universities I was at they also had 4-5 digit dialing. One place changed over from 4 digits to 5 digits when I was there when they ran out of numbers. What a mess. To go outside it was the usual dial 9 first.
Even if the new equipment would have supported four digit dialing, there are sometimes factors involved other than the customers’ preference. When I was a kid, you didn’t have to use the area code if you were dialing within the same one. Then part of the city got a new area code - and there were issues because people forgot the area code when calling someone in the same city but a different area code. Then even more area codes were added as overlays, where I might have a different area code than my next door neighbor - there was a fear (I don’t know if it was realistic*) that businesses would be impacted because people would prefer to order delivery from a restaurant or retailer with the same area code they had and at that point ten digit dialing became mandatory. Then , about three or four years ago, there was a new three digit number established for a national suicide prevention helpline - 988. This meant that any area codes that still had 7 digit dialing and a 988 exchange had to go to 10 digit dialing. I suppose they could have eliminated the 988 exchange instead but that would have involved changing a lot of phone numbers.
* It might have been - years later people would pay extra to get a 718 or 212 number for their cell phone.
We could dial four digits in the tiny (<80 people) “town” I grew up in. Sometime in the late 80s/early 90s it got updated and we had to dial five digits (last digit of prefix plus four digits); by the mid-90s it got updated again and we had to dial a whole SEVEN digits (there were complaints about all that extra work).
Maybe. We lived in a housing development in Brewster, NY, from the summer of '79 to the summer of '83. The development had its own little phone list; we could dial anyone else in the development with just a few numbers.