“555” and related telephone prefixes | Hacker News Reader

“555” and related telephone prefixes

computer.rip

41 pointsmiles10 comments

555 had another use. When I had service from Bell of Pennsylvania, you could call 800-555-xxxx (I forget the last four, but it wasn't 1212) to get connected to billing customer service.

The author also mentions the 500 area code. But he missed its use by AT&T for roaming numbers (before "roaming" meant cellular).

I had 500-674-9845. It could be programmed to ring you at different phones at different times of the day. For example, it could be set to forward all calls to your office Monday through Friday 9am to 5pm, then to your club from 5pm to 7pm, and then to your home from 7pm to 9am.

It was very useful, but these were the days of the PBX wild west when cost-reduced computers made poor quality PBX companies attractive to small and medium-sized businesses. The list of valid area codes and prefixes came in quarterly from your rep via sneakernet. Two places I worked over two years didn't have very good PBX vendors, so in both cases people at my work could not call me on my 500 number. One boss became particularly irate about not being able to reach me after hours.

He does talk about that use of 500s:

> In 1993, NANP allocated the 500 NPA to Personal Communications Service (PCS), not to be confused with Personal Communications Service (PCS). ... [T]he former refers to... EasyReach 700 all over again, except for now it's called True Connections.

1-700-555-4141 used to tell you who was set up as your primary interexchange carrier. It might still if you're on a truly old-school land line.

There's a slightly interesting history to this feature, which should still work on a conventional land line. It was mandated as a partial solution to a scam called "slamming," in which a disreputable long-distance carrier would inform a customer's local exchange carrier that they had 'requested' that their default long distance carrier be changed... without their knowledge.

"Slamming" is not to be confused with "Cramming," another common telephone billing scam of the post-breakup period, because all of these got fun rhyming names.

Yup. PIC locks for the win.

Also, it was neat to use the equal access codes to dial around and see what numbers mapped to what carriers, and what their "welcome to XYZ" recordings sounded like.

Ah, being a kid and being bored.

When I lived in New Zealand, I once had an American caller ask me for the number of our other office, which happened to start with 555 (which has no special significance in NZ). It took me some time to convince her that I wasn't trying to fob her off with a fake number, because obviously everybody knows 555 numbers aren't real.

When I see 555, I think of the timer IC.

Of course all this is USA-specific.

In my area of Ireland, around the early 90s, the pattern for all local numbers changed from 091-85xxx to 091-555xxx. You could omit the 091 when dialling local numbers. Since all my friends lived nearby, most of my dialling (and my own number) started with 555.

> Of course all this is USA-specific.

Well, to get a bit pedantic this all applies to everywhere covered by the NANP which doesn't _just_ cover the US.[0] Though the US is by far the most prominent country covered.

[0] https://en.wikipedia.org/wiki/List_of_country_calling_codes#...

New Zealand is on that list.

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