How to use the converter
Type anything — your name, a flight booking reference, a postcode, a Wi-Fi password — and each letter and digit becomes its spelling-alphabet word. Letters are separated by spaces and a slash marks the end of each word, so “BK7 39X” becomes:
Bravo Kilo Seven / Tree Niner X-ray
Punctuation is passed through unchanged. To go the other way, paste code words into the lower box; the converter accepts the official spellings and common variants (Alpha, Juliet, Whisky, X-ray or Xray, Nine or Niner), in any letter case.
The ICAO / NATO spelling alphabet
The words and spellings below are exactly as published by the International Civil Aviation Organization, which cites Annex 10, Volume II. Pronunciation guides follow ICAO’s Manual of Radiotelephony (capital letters show the stressed syllables).
| Letter | Code word | Say it | Letter | Code word | Say it |
|---|---|---|---|---|---|
| A | Alfa | AL-FAH | N | November | NO-VEM-BER |
| B | Bravo | BRAH-VOH | O | Oscar | OSS-CAH |
| C | Charlie | CHAR-LEE or SHAR-LEE | P | Papa | PAH-PAH |
| D | Delta | DELL-TAH | Q | Quebec | KEH-BECK |
| E | Echo | ECK-OH | R | Romeo | ROW-ME-OH |
| F | Foxtrot | FOKS-TROT | S | Sierra | SEE-AIR-RAH |
| G | Golf | GOLF | T | Tango | TANG-GO |
| H | Hotel | HO-TELL | U | Uniform | YOU-NEE-FORM or OO-NEE-FORM |
| I | India | IN-DEE-AH | V | Victor | VIK-TAH |
| J | Juliett | JEW-LEE-ETT | W | Whiskey | WISS-KEY |
| K | Kilo | KEY-LOH | X | X-ray | ECKS-RAY |
| L | Lima | LEE-MAH | Y | Yankee | YANG-KEY |
| M | Mike | MIKE | Z | Zulu | ZOO-LOO |
Numbers: why “niner” and “fife”
Annex 10 also fixes how digits are spoken in English radiotelephony. Several differ from everyday English — most noticeably 3 is TREE, 5 is FIFE and 9 is NIN-er. Numbers are normally read digit by digit (“one two five” rather than “one hundred twenty-five”), except for whole hundreds and thousands in altitudes and similar values.
| Digit | ICAO word | Pronunciation |
|---|---|---|
| 0 | Zero | ZE-RO |
| 1 | One | WUN |
| 2 | Two | TOO |
| 3 | Tree | TREE |
| 4 | Four | FOW-er |
| 5 | Fife | FIFE |
| 6 | Six | SIX |
| 7 | Seven | SEV-en |
| 8 | Eight | AIT |
| 9 | Niner | NIN-er |
With the Numbers setting on “Plain English”, the same example reads Bravo Kilo Seven / Three Nine X-ray.
Why Alfa and Juliett are spelled that way
The alphabet was designed for speakers of many languages, not just English. ICAO’s account of its history notes that “alpha” could be mispronounced by people who do not know that ph sounds like f, so the official spelling is Alfa; and a single final t in “Juliet” might be silent to French speakers, so it is Juliett. Some English-language lists use Alpha and Juliet anyway — they are understood, but the ICAO forms are the standard.
A short history
Before 1956 several spelling alphabets competed. The US and British militaries used “Able, Baker, Charlie…” during the Second World War, and in 1951 civil aviation adopted an alphabet developed with linguist Jean-Paul Vinay that included Coca, Metro, Nectar, Union and Extra. After further testing, five words were replaced — giving Charlie, Mike, November, Uniform and X-ray — and ICAO implemented the final version on 1 March 1956, according to its Annex 10 history. NATO made the same alphabet effective for its forces on 1 March 1956, according to NATO’s own history page, which is why it is widely called the NATO phonetic alphabet. (Strictly it is a spelling alphabet: the words stand for letters, not sounds.)
Using it on the phone
- Say the code words at an even pace, and pause briefly between words of the original text.
- For mixed-case passwords, say “capital” before an uppercase letter; the alphabet itself has no case.
- Read numbers digit by digit, and repeat the whole sequence back to confirm.
Print the NATO phonetic alphabet chart to keep by the phone, or spell the same text in Morse code.
Spelling email addresses, codes and passwords
Punctuation has no code word, so say it plainly: “at” for @, “dot” for a full stop, “dash” or “hyphen” for -, and “underscore” for _. The converter passes these characters through unchanged so you can see where to say them. For example, “jo.lee@mail.com” becomes:
Juliett Oscar . Lima Echo Echo @ Mike Alfa India Lima . Charlie Oscar Mike
Booking references and serial numbers often mix letters and digits that are easily confused — O and 0, I and 1, S and 5. Spelling them as Oscar and Zero, India and One, Sierra and Fife removes the doubt, which is the whole point of the alphabet.