How many possible phone numbers can there be in a single area code?

Answer 1

The number of "lines" or "phone numbers" assigned to one area code will vary as a function of the number of exchanges in that area code. Let's look.

In the 555 area code, in the 111 exchange, there are 10,000 numbers that can be dialed. 555.111.0000, 555.111.0001,... 555.111.9999. With 10,000 numbers per exchange, we can calculate the number of numbers or "lines" by multiplication. Look up the number of exchanges in a given area code and make a quick calculation.

For an "absolute" answer, consider that if we could use all the numbers for exchanges (000, 001, 002,... 999), there are 1,000 possible exchanges. With 1,000 possible exchanges and 10,000 possible numbers per exchange, that works out to 1,000 times 10,000 or 10,000,000 (ten million) possible numbers or "lines" per area code.

However, that number assumes that every single possible telephone number is assigned. In the US and Canada, the exchange code cannot begin with 0 or 1, and the second and third digits cannot both be 1 (e.g., 411, 911, etc.). Most area codes also protect prefixes that use the same digits as another area code nearby. For example, area code 415 is adjacent to area code 650, so there is no 415-650 prefix, nor a 650-415 prefix.

That reduces the possible numbers per area code to a bit under 8 million.

In addition, only a fraction of the numbers within each prefix are assigned and in use at any given time. When a telephone line is disconnected, the number is left unavailable for at least a few months to reduce the level of misdials.

Answer 2

In the USA and Canada, always three digits.

For example, 212 for Manhattan or 603 for New Hampshire.

In other countries, it is often different.

In the United Kingdom, for example, codes can range from 3 digits in big urban areas (such as 020 for London) to as many as 6 digits (such as 015394 for the small town of Hawkshead).

Some countries do not have area codes at all. In Denmark, for example, every phone simply has an eight digit number which is always dialled in full.

Answer 3

It depends which country you're in. In the UK, numbers usually have either a 4-digit code with seven digits, or 5-digit code plus six digits. Therefore - theoretically, those with a 4-digit code can have up to 9,999,999 numbers allocated to it. those with 5-digits could have up to 999,999 numbers.

In practice, however - this rarely happens !

Answer 4

Each area code has about 7,800,000 different usable phone numbers.

(Although there are technically 10 million seven-digit phone number combination available in each area code, some numbers aren't available, such as 911, 411, and numbers starting with 0 or 1.)

Answer 5

There are 800 different combinations of area codes in the US. Not all of these are currently used, they are out of service or reserved for specific reasons.