In the United States and Canada phone numbers with letters were commonly used in the mid-20th century particularly between the 1940s and 1960s. This system was known as the North American Numbering Plan (NANP).
Under the NANP each phone number was comprised of a three-digit area code, followed by a three-digit exchange code, and then a four-digit line number. In order to make these numbers easier to remember the letters corresponding to the digits on the telephone keypad were also used. For example the exchange code would correspond to the numbers 55 and 66 on the phone keypad.
This allowed phone numbers to
Be represented with words that were easier to remember. This was particularly useful for businesses and advertisers who wanted to make their phone numbers more memorable to customers.
However as phone usage increased and the demand for phone Jamaica Mobile Number List numbers grew it became necessary. To move away from the use of letters in phone numbers. In the 1960s the NANP switched to an all-digit numbering system which is still in use today. for letters in phone numbers but it also made phone numbers more difficult to remember without the aid of mnemonic devices or repetition. Followed by a three-digit exchange code
And then a four-digit line number
Order to make these numbers easier to remember the letters corresponding to. The digits on the telephone keypad were also used. For example the exchange code would correspond to the India Lead 55 and 66 on the phone keypad. This allowed phone numbers to be represented with words that were easier to remember such as “555-KLondike”. This was particularly useful for businesses and advertisers. Who wanted to make their phone numbers more memorable to customers.
