How phone words work

Letters on the keypad

Every phone keypad carries letters on the keys 2 to 9. The 1 and 0 keys carry none. The layout is the international standard ITU-T E.161, and it is based on the letters American phones carried from the 1930s.

Where the letters came from

For much of the 20th century, many American phone numbers began with two letters taken from the name of the local telephone exchange, followed by five digits. Callers dialed the letters along with the digits. The Bell System began replacing exchange names with all-number calling in 1958, but the letters stayed on the dial.

Older North American dials had no Q or Z: the 7 carried PRS and the 9 carried WXY. Today's layout puts Q on 7 and Z on 9, so every letter of the alphabet can be dialed.

How a word fits into a number

A US phone number has ten digits: a three-digit area code, a three-digit exchange code and a four-digit line number. A word can use any of the last seven digits. A four-letter word fills the line number exactly (XXX-XXX-ROOF), a five-letter word reaches back into the exchange code (XXX-XX-PIZZA), and a seven-letter word has to fill all seven digits after the area code.

That is why short words are easy to find and long ones are rare. A seven-letter word matches at most one number in each area code, and that number has to be free and for sale.

One set of digits, several words

Each key carries three or four letters, so the same digits spell more than one word. The digits that spell LAW (529) also spell JAY and LAY. Listings on this site show the word the number was matched to and, where there are any, other words the same digits spell.

It works the other way too: before you buy, check that your digits don't also spell something you wouldn't want on your sign.

How callers dial it

Callers press the keys that carry the letters, so a word number dials like any other number. Many people still like to see the digits, so print both: the word to remember and the digits to dial.