The US emergency telephone number 911 seems to be almost always pronounced as

nine one one

whereas the Porsche model is typically pronounced as

nine eleven

One reason I can think of for preferring "nine one one" for the phone number is that there is no "eleven" key on a phone. On the other hand, "0800" is often pronounced "o eight hundred".

Is there a logical or historical reason for the different pronunciations?

  • 17
    Six of one, half a dozen of the other.
    – Robusto
    Commented Dec 25, 2014 at 21:56
  • 10
    Ninety-one one.
    – The111
    Commented Dec 26, 2014 at 3:55
  • 1
    This question appears to be off-topic because it is too localized. Commented Dec 27, 2014 at 3:22

6 Answers 6


How a car manufacturer names its models is more of a marketing preference than anything, but in general you'll find that the Porche model is the norm. Ask any schoolchild to read aloud the number "911" and you'll get "nine hundred and eleven", not "nine one one".

The telephone number 9-1-1 was, as you speculated, spelled out specifically to prevent people - particularly children - from getting confused looking for the "eleven" key on the telephone.

I have heard this anecdotally countless times, but I'm having a hard time finding an authoritative source. Closest I can come are various "history of 911" websites like this one:

Dr. Phil Shaenman, head of the U.S. Fire Administration's research department, authored a paper explaining that children should be taught to dial "nine-one-one," and not "nine-eleven." He pointed out that a child's conceptual abilities prevent them from recognizing the difference between "11" and "1-1."


911, the phone number, involves a physical pressing of three keys while the car model can be thought of as shorthand for "nine hundred eleven" and the date is a month (9) and a day (11).

The reason 800 in a phone number is used differently, I think, is that it is just one portion of a longer number. Since 800 was the sole toll free long distance exchange for a long time and was used primarily by businesses, advertising probably played a role as 1-8 hundred- whatever flows better in jingles than 1-8-0-0-whatever. Also, since 1-8 hundred compresses the number of elements being conveyed, it makes it easier to remember (IIRC the psychological concept is called chunking - grouping things together to increase ability to remember).

  • I like the mention of chunking (though I'm unsure if there is a difference in terminology between simply grouping numbers spatially, and changing pronunciation as is meant here), and think it's worth combining this concept with the mention of children's conceptual abilities in @Lynn's answer. Chunking adds a layer of abstraction between the information (sequence of digits) and the words spoken, which a young child may not have adequate experience to relate the two forms. In the emergency line context, clear understanding is vital, where in other contexts it may not be. Commented Dec 27, 2014 at 16:29
  • @AnthonyBurleigh Not a psychologist, but marrying one: chunking definitely seems to be used for any strategy that groups pieces of data together in a single unit to aid memorization and facilitate thought about the chunks. It's a pretty broad, high-level term that can cover a lot of specific strategies, it seems to me.
    – KRyan
    Commented Dec 27, 2014 at 16:53
  • 2
    Keys? What are these "keys"? You stick your finger into the hole and turn the dial.
    – Hot Licks
    Commented Dec 28, 2014 at 3:29

The Porsche 911 was originally named the "901" but that had to be changed to "911" because Peugeot had the trademark for cars named (X0Y). My guess is that Porsche was already thinking of the car as the "9" series, and the first model's name of the 9 series was changed to "nine eleven" because calling it the "nine one one" wouldn't make sense to them.

  • 2
    Can you really trademark numbers? Commented Dec 25, 2014 at 23:49
  • 4
    I can't link to the result page, but Boeing has a trademark on "737" www.uspto.gov Apparently intel tried to trademark several x86 numbers over the years without success so there is some discretion used when granting trademarks. Also, keep in mind trademarks, patents, and copyrights are all separate.
    – BurnsBA
    Commented Dec 26, 2014 at 1:11
  • 1
    French trademark, not US.
    – MSalters
    Commented Dec 26, 2014 at 21:15
  • 3
    Not even a number. A whole class of numbers.
    – John Tyree
    Commented Dec 26, 2014 at 22:37
  • 1
    @TimLymington There are certainly places where you can't trademark numbers, as that's why Intel's processor line went 8086, 80186, 80286, 80386, 80486, Pentium. They started using a name to force clone makers to use a different name. Commented Dec 27, 2014 at 1:26

All phone numbers are actually spelled out as separate digits in English, hence nine-one-one (although this is not necessarily the case in other languages, eg. a phone number of 823 4567 might be easily pronounced as the equivalent of eight twenty-three forty-five sixty-seven in a different language).

Marketing or other numbers like this Porsche model number have no such strict rules, they depend much more on established customs. The Porsche happens to come from Germany and the German reference to the model was Neunelfer (or later, with is popularity, even simply Elfer) all along, because this is the standard way to pronounce such numbers in German.

  • This isn't always the case in the UK. e.g. the 0800 prefix for free calls is commonly pronounced "Oh Eight Hundred" Commented Dec 27, 2014 at 16:31
  • 1
    Correct. In the US, for other than "eight hundred" numbers, it is normal to "spell out" phone numbers, a digit at a time. If you ask someone their number, they are extremely unlikely to say "five million, two hundred and eighty-three thousand, six hundred and fifty two", but rather will say "five two eight, three six five two".
    – Hot Licks
    Commented Dec 28, 2014 at 3:35

In pronouncing or spelling-out numbers we have competing pressures of accuracy, completion, simplicity and concision.

If anything we should 911 should be "nine hundred and eleven". The form "nine-eleven" can be understood either as a change to breaking it into units before forming words (hence 911 becomes 9 11 before becoming "nine eleven") or as an abbreviation where the "hundred" is omitted.

We are more likely to do this when the number has no numerical value, which is the case with both the name and the phone number (they are not one greater than 910 or otherwise arithmetically meaningful, but merely identifiers or names), because their lacking meaning as whole numbers means no loss of meaning happens when our speaking them hides the arithmetic value. So for something like "what is 410 + 501?" or "What is the second-highest three-digit Sophie Germain prime?" we'd be more likely to say "nine hundred and eleven" than we would with such codes as the two cases you give here.

Phone numbers are particularly likely to be given as individual numbers originally because they were very small (always one, two or three-figures*) and generally managed by the operators as individual units and later when rotary (and later again push-button) dialers became common, by individuals.

The advantage of individual digits decreases as numbers become larger. Some cultures deal with this by grouping a different way (in some places grouping into double-digit units is common) but English-speaking countries tend not to do this. We do though spot patterns and so e.g. "double-four" and "triple-seven" will jump out at us and so become how we speak out the number. We also have a tendency to spot hundreds because they're significant in our decimal numeric system and something we commonly round to, so "oh eight-hundred" is more likely to appear than "oh eight oh oh". The fact that hundreds often appear in special-priced area codes that are free, higher-priced or local-priced from whichever area they are called from only serves to reinforce this (for example 0800 in the UK and Germany and 1800 in Ireland and the US are all freephone numbers).

*Indeed the choice of 911 comes at a time when many exchanges were fixed on three digits. The obvious choice of starting at 111 [a low number and the one most easily dialled on a rotary dialer] was already taken on some exchanges and sometimes mis-dialled by faulty equipment so while some places did indeed pick that as the number for emergency services, 999 and 911 being well into the area that were not yet taken were also used. New Zealand used 111 because the mis-dialing issue happened more often with 999 for their pulse-dialing system.


That the emergency number 911 is pronounced nine-one-one is probably a standard to avoid confusion or doubt by either children or non-natives to the English language. Pronouncing the number as nine hundred and eleven could be misinterpreted as 90011, hence the emphasis of three digits.

This is also a deal in most European countries, where 112 is the emergency number and pronounced 1-1-2 in the languages I know and for all I know in other languages too.

one-one-two     (English),
ein-eins-zwei   (German),
et-et-to        (Danish),
einn-einn-tveir (Icelandic)
  • Is there any truth to the following line from Married with Children: "In which case, call 911 or as they say in Wanker County, Nine hundred and eleven."? Commented Dec 27, 2014 at 20:24

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