Standard & RadiotelephonyITU-R & ICAO Annex 10Updated: September 2026

NATO Phonetic Alphabet & Morse Code Chart

Complete A–Z radiotelephony spelling alphabet alongside international Morse code equivalents, synchronized pure-tone audio playback, and historical comparisons with WWII Able Baker, 1927 ITU, and RAF alphabets.

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NATO Phonetic Spelling (ICAO Standard):

Charlie Quebec [SPACE] Charlie Quebec [SPACE] Delta Echo [SPACE] Kilo WUN Alfa Whiskey

WWII Able Baker: Charlie Queen [SPACE] Charlie Queen [SPACE] Dog Easy [SPACE] King 1 Able William
International Morse Code (CW):

-.-. --.- / -.-. --.- / -.. . / -.- .---- .- .--

10 characters

NATO Phonetic Alphabet A–Z & Historical Comparison

Explore every letter with dedicated audio playback, authentic pronunciations, and side-by-side historical tables.

A

Alfa

[AL-fah]
.-
1· 1- (5b)
WWII Able Baker:Able
1927 ITU World City:Amsterdam
RAF 1942:Ace
Note: Spelled 'Alfa' with 'f' (not Alpha) so native Spanish, Italian, and multilingual speakers articulate /f/ without hesitation.
B

Bravo

[BRAH-voh]
-...
3· 1- (9b)
WWII Able Baker:Baker
1927 ITU World City:Baltimore
RAF 1942:Beer
C

Charlie

[CHAR-lee]
-.-.
2· 2- (11b)
WWII Able Baker:Charlie
1927 ITU World City:Casablanca
RAF 1942:Charlie
D

Delta

[DELL-tah]
-..
2· 1- (7b)
WWII Able Baker:Dog
1927 ITU World City:Danemark
RAF 1942:Don
E

Echo

[ECK-oh]
.
1· 0- (1b)
WWII Able Baker:Easy
1927 ITU World City:Edison
RAF 1942:Edward
F

Foxtrot

[FOKS-trot]
..-.
3· 1- (9b)
WWII Able Baker:Fox
1927 ITU World City:Floride
RAF 1942:Freddie
G

Golf

[GOLF]
--.
1· 2- (9b)
WWII Able Baker:George
1927 ITU World City:Gallipoli
RAF 1942:George
H

Hotel

[hoh-TELL]
....
4· 0- (7b)
WWII Able Baker:How
1927 ITU World City:Havane
RAF 1942:Harry
Note: Stress is on the second syllable ('hoh-TELL') to guarantee clarity even if an operator drops the initial aspirate 'h'.
I

India

[IN-dee-ah]
..
2· 0- (3b)
WWII Able Baker:Item
1927 ITU World City:Italia
RAF 1942:Ink
J

Juliett

[JEW-lee-ETT]
.---
1· 3- (13b)
WWII Able Baker:Jig
1927 ITU World City:Jérusalem
RAF 1942:Johnnie
Note: Spelled with double 'tt' internationally so French speakers pronounce the final /t/ rather than treating single 't' as silent ('Ju-li-ay').
K

Kilo

[KEY-loh]
-.-
1· 2- (9b)
WWII Able Baker:King
1927 ITU World City:Kilogramme
RAF 1942:King
L

Lima

[LEE-mah]
.-..
3· 1- (9b)
WWII Able Baker:Love
1927 ITU World City:Liverpool
RAF 1942:London
Note: Pronounced 'LEE-mah' (like the capital of Peru), never 'LY-mah' (like the bean).
M

Mike

[MIKE]
--
0· 2- (7b)
WWII Able Baker:Mike
1927 ITU World City:Madagascar
RAF 1942:Monkey
N

November

[no-VEM-ber]
-.
1· 1- (5b)
WWII Able Baker:Nan
1927 ITU World City:New-York
RAF 1942:Nuts
Note: Stress is firmly on the middle syllable: 'no-VEM-ber'.
O

Oscar

[OSS-cah]
---
0· 3- (11b)
WWII Able Baker:Oboe
1927 ITU World City:Oslo
RAF 1942:Orange
P

Papa

[pah-PAH]
.--.
2· 2- (11b)
WWII Able Baker:Peter
1927 ITU World City:Paris
RAF 1942:Pip
Note: Stress is on the second syllable: 'pah-PAH' to prevent confusion with English 'popper' or French 'papa'.
Q

Quebec

[keh-BEK]
--.-
1· 3- (13b)
WWII Able Baker:Queen
1927 ITU World City:Québec
RAF 1942:Queen
Note: Pronounced with French Canadian phonology: 'keh-BEK', not English 'kwi-beck'.
R

Romeo

[ROH-me-oh]
.-.
2· 1- (7b)
WWII Able Baker:Roger
1927 ITU World City:Rome
RAF 1942:Robert
S

Sierra

[see-AIR-rah]
...
3· 0- (5b)
WWII Able Baker:Sugar
1927 ITU World City:Santiago
RAF 1942:Sugar
T

Tango

[TANG-go]
-
0· 1- (3b)
WWII Able Baker:Tare
1927 ITU World City:Tripoli
RAF 1942:Toc
U

Uniform

[YOU-nee-form]
..-
2· 1- (7b)
WWII Able Baker:Uncle
1927 ITU World City:Upsala
RAF 1942:Uncle
Note: Also pronounced 'OO-nee-form' by international aircrews to suit non-English palatalization.
V

Victor

[VIK-tah]
...-
3· 1- (9b)
WWII Able Baker:Victor
1927 ITU World City:Valence
RAF 1942:Vic
W

Whiskey

[WISS-key]
.--
1· 2- (9b)
WWII Able Baker:William
1927 ITU World City:Washington
RAF 1942:William
X

X-ray

[ECKS-ray]
-..-
2· 2- (11b)
WWII Able Baker:X-ray
1927 ITU World City:Xantippe
RAF 1942:X-ray
Y

Yankee

[YANG-key]
-.--
1· 3- (13b)
WWII Able Baker:Yoke
1927 ITU World City:Yokohama
RAF 1942:Yorker
Z

Zulu

[ZOO-loo]
--..
2· 2- (11b)
WWII Able Baker:Zebra
1927 ITU World City:Zurich
RAF 1942:Zebra
ICAO Annex 10 & ITU Standard Numbers

Radiotelephony Numbers (0–9) & Pronunciation Rules

Numbers in radiotelephony are modified phonetically (such as TREE, FOW-ER, FIFE, and NIN-ER) to ensure unambiguous reception across static-heavy frequencies.

0-----
ZEE-RO
[ZEE-ro]
ITU Maritime / Telegraph:NADAZERO

Articulated with sharp 'ee' to distinguish from English letter 'O' (Oscar).

1.----
WUN
[WUN]
ITU Maritime / Telegraph:UNAONE

Crisp single-syllable pronunciation preventing vowel drag.

2..---
TOO
[TOO]
ITU Maritime / Telegraph:BISSOTWO

Hard dental plosive /t/ with sustained high back vowel.

3...--
TREE
[TREE]
ITU Maritime / Telegraph:TERRATHREE

Altered to 'TREE' because non-English speakers often pronounce 'three' as 'free' or 'sree'.

4....-
FOW-ER
[FOW-er]
ITU Maritime / Telegraph:KARTEFOUR

Pronounced with two deliberate syllables ('FOW-er') so it cannot be confused with the preposition 'for'.

5.....
FIFE
[FIFE]
ITU Maritime / Telegraph:PANTAFIVE

Pronounced 'FIFE' with a hard unvoiced terminal 'f' so it can never be mistaken for 'fire'.

6-....
SIX
[SIX]
ITU Maritime / Telegraph:SOXISIX

Distinctive sibilant-stop-sibilant /sɪks/ envelope cuts through carrier whine.

7--...
SEV-EN
[SEV-en]
ITU Maritime / Telegraph:SETTESEVEN

Articulated with two crisp syllables to prevent confusion with monosyllabic digits.

8---..
AIT
[AIT]
ITU Maritime / Telegraph:OKTOEIGHT

Emphasizes the sharp dental stop /t/ to stand out from background noise.

9----.
NIN-ER
[NIN-er]
ITU Maritime / Telegraph:NOVENINE

Altered to two syllables ('NIN-er') to eliminate confusion with the German negative 'nein' ('no').

Voice Prowords ⇄ CW Prosigns

Voice Radiotelephony Prowords vs. Morse Code Prosigns

Radiotelephony (voice) and radiotelegraphy (CW / Morse) share an identical procedural grammar. In voice, operators speak standardized prowords; in Morse code, operators send run-together prosigns.

ROGERCW: R (.-.)

I have received and understood your last transmission.

Operational Protocol:Voice: 'Tower, Roger, wind 270 at 12.' / CW: 'R 73 TU EE'
OVERCW: K (-.-)

My transmission is ended and I expect a response from you.

Operational Protocol:Voice: 'Coast Guard, this is vessel Osprey, OVER.' / CW: 'DE W1AW K'
OUTCW: SK (...-.-) or CL

This transmission is ended and no response is expected (station closing).

Operational Protocol:Voice: 'Dispatch, Unit 4 is 10-8, OUT.' / CW: 'TNX FER QSO 73 SK'
SAY AGAINCW: IMI (..--..) or ?

Repeat all, or the specified part, of your last transmission.

Operational Protocol:Voice: 'Say again coordinates.' / CW: '? QTH ?'
STANDBY / WAITCW: AS (.-...)

I must pause for a few seconds or minutes; wait for me.

Operational Protocol:Voice: 'Standby for weather update.' / CW: 'AS 2 MIN'
WILCOCW: R + OK

I have received, understood, and WILL COMPLY with your instructions.

Operational Protocol:Voice: 'Maintain 3,000 feet, WILCO.' (Note: never say 'Roger Wilco')
MAYDAYCW: SOS (...---...)

Distress signal — immediate grave danger to life or vessel.

Operational Protocol:Voice: 'MAYDAY MAYDAY MAYDAY' / CW: 'SOS SOS SOS DE WX1'
PAN-PANCW: XXX (-..- -..- -..-)

Urgency signal — serious safety issue not yet imminent peril.

Operational Protocol:Voice: 'PAN-PAN PAN-PAN PAN-PAN' / CW: 'XXX XXX DE N0CALL'

The Acoustic Science Behind the NATO Phonetic Alphabet

The NATO phonetic alphabet is not merely a collection of memorable words; it is an acoustically engineered communication system developed to survive the worst possible transmission conditions. Between 1948 and 1951, under the direction of French-Canadian linguist Dr. Jean-Paul Vinay at the Université de Montréal, researchers conducted psychoacoustic tests across 100,000 language speakers representing over 30 countries.

Their scientific mandate was clear: identify 26 words whose acoustic frequency spectra (formant frequencies, consonant bursts, and vowel durations) remain 100% distinct even when filtered through low-fidelity aircraft headsets, overwhelmed by 100-decibel radial engine roar, or degraded by high-frequency atmospheric noise.

1. Formant Separation

Every vowel in the NATO alphabet occupies distinct first and second vocal formants (F1/F2), preventing vowel shifts caused by non-native accents.

2. Syllabic Cadence

Nearly all words feature 2 to 3 syllables with deliberate stress patterns (e.g., no-VEM-ber, hoh-TELL, pah-PAH) that survive radio squelch clipping.

3. Plosive Consonants

Initial consonant bursts (/b/, /tʃ/, /d/, /k/, /p/, /t/) generate distinct transient acoustic energy spikes visible on audio oscilloscopes.

Why Are “Alfa” and “Juliett” Intentionally Misspelled?

Aviation novices often assume that the spellings “Alfa” (with an f) and “Juliett” (with two ts) are typographical errors. In fact, these international spellings are legally codified in ICAO Annex 10 (Aeronautical Telecommunications) and ITU Radio Regulations:

  • Alfa (not Alpha): In Spanish, Italian, and various Slavic languages, the digraph “ph” is unfamiliar or does not automatically signify the voiceless labiodental fricative /f/. Spelling the word with an explicit “f” ensures that controllers in Madrid, Rome, or Buenos Aires pronounce the first letter without hesitation.
  • Juliett (not Juliet): In French, an unaccented trailing consonant “t” is grammatically silent. A French speaker reading “Juliet” would naturally articulate it as “Ju-lee-ay”, dropping the essential ending consonant. Adding the second “t” forces native French speakers to articulate the hard plosive /t/ (“JEW-lee-ETT”).

Twin Pillars: Why Search-and-Rescue & Ham Radio Train Both Systems

Why do radio operators, military signalers, and emergency volunteers continue to train in both the NATO phonetic alphabet and Morse code? The answer lies in digital signal physics and the electromagnetic spectrum:

Single sideband (SSB) voice transmission requires an audio bandwidth of approximately 2,700 to 3,000 Hertz and a signal-to-noise ratio (SNR) of at least +6 to +10 dB for human ears to decipher words. Under severe solar geomagnetic storms, hurricane conditions, or over thousands of miles across oceans, voice signals rapidly dissolve into unintelligible hiss.

In contrast, continuous wave (CW / Morse code) concentrates all transmitter power into a microscopic 50 Hertz bandwidth. A human ear trained in Morse code can copy signals at -15 dB SNR — buried deeply below the noise floor where no voice or digital telephone can connect. When voice channels fail, operators switch their transceivers to CW Morse code to establish life-saving rescue links.

Questions & Answers

Frequently Asked Questions About NATO Phonetics & Morse Code

Frequently Asked Questions

The NATO phonetic alphabet (officially the International Radiotelephony Spelling Alphabet, standardized by ICAO, ITU, IMO, and NATO) assigns 26 distinct, acoustically optimized code words (Alfa, Bravo, Charlie... Zulu) to each letter of the alphabet. In radiocommunications, voice transmissions (radiotelephony) and continuous wave telegraphy (CW / Morse code) are twin operating modes. Every letter in the NATO phonetic alphabet directly maps to an international Morse code pattern (such as Alfa to '.-' and Bravo to '-...'). Operators frequently switch between voice phonetics and Morse code when signals degrade due to atmospheric static or long-distance fading.