The radiocommunication division of the International Telecommunication Union uses the following letter codes to identify its member countries. Eight countries are assigned single-letter codes, while the rest have codes three letters in length. The names of the countries are shown as mentioned in the ITU's official list.
| Code | Country |
| A | |
|---|---|
| AFG | Afghanistan |
| AFS | South Africa (Republic of) |
| AGL | Angola (Republic of) |
| ALB | Albania (Republic of) |
| ALG | Algeria (People's Democratic Republic of) |
| AND | Andorra (Principality of) |
| ARG | Argentine Republic |
| ARM | Armenia (Republic of) |
| ARS | Saudi Arabia (Kingdom of) |
| ATG | Antigua and Barbuda |
| AUS | Australia |
| AUT | Austria |
| AZE | Azerbaijani Republic |
| B | |
| B | Brazil (Federative Republic of) |
| BAH | Bahamas (Commonwealth of the) |
| BDI | Burundi (Republic of) |
| BEL | Belgium |
| BEN | Benin (Republic of) |
| BFA | Burkina Faso |
| BGD | Bangladesh (People's Republic of) |
| BHR | Bahrain (Kingdom of) |
| BIH | Bosnia and Herzegovina |
| BLR | Belarus (Republic of) |
| BLZ | Belize |
| BOL | Bolivia (Republic of) |
| BOT | Botswana (Republic of) |
| BRB | Barbados |
| BRM | Myanmar (Union of) |
| BRU | Brunei Darussalam |
| BTN | Bhutan (Kingdom of) |
| BUL | Bulgaria (Republic of) |
| C | |
| CAF | Central African Republic |
| CAN | Canada |
| CBG | Cambodia (Kingdom of) |
| CHL | Chile |
| CHN | China (People's Republic of) |
| CLM | Colombia (Republic of) |
| CLN | Sri Lanka (Democratic Socialist Republic of) |
| CME | Cameroon (Republic of) |
| COD | Democratic Republic of the Congo |
| COG | Congo (Republic of the) |
| COM | Comoros (Union of the) |
| CPV | Cape Verde (Republic of) |
| CTI | Côte d'Ivoire (Republic of) |
| CTR | Costa Rica |
| CUB | Cuba |
| CVA | Vatican City State |
| CYP | Cyprus (Republic of) |
| CZE | Czech Republic |
| D | |
| D | Germany (Federal Republic of) |
| DJI | Djibouti (Republic of) |
| DMA | Dominica (Commonwealth of) |
| DNK | Denmark |
| DOM | Dominican Republic |
| E | |
| E | Spain |
| EGY | Egypt (Arab Republic of) |
| EQA | Ecuador |
| ERI | Eritrea |
| EST | Estonia (Republic of) |
| ETH | Ethiopia (Federal Democratic Republic of) |
| F | |
| F | France |
| FIN | Finland |
| FJI | Fiji (Republic of) |
| FSM | Micronesia (Federated States of) |
| G | |
| G | United Kingdom of Great Britain and Northern Ireland |
| GAB | Gabonese Republic |
| GEO | Georgia |
| GHA | Ghana |
| GMB | Gambia (Republic of the) |
| GNB | Guinea-Bissau (Republic of) |
| GNE | Equatorial Guinea (Republic of) |
| GRC | Greece |
| GRD | Grenada |
| GTM | Guatemala (Republic of) |
| GUI | Guinea (Republic of) |
| GUY | Guyana |
| H | |
| HND | Honduras (Republic of) |
| HNG | Hungary (Republic of) |
| HOL | Netherlands (Kingdom of the) |
| HRV | Croatia (Republic of) |
| HTI | Haiti (Republic of) |
| I | |
| I | Italy |
| IND | India (Republic of) |
| INS | Indonesia (Republic of) |
| IRL | Ireland |
| IRN | Iran (Islamic Republic of) |
| IRQ | Iraq (Republic of) |
| ISL | Iceland |
| ISR | Israel (State of) |
| J | |
| J | Japan |
| JMC | Jamaica |
| JOR | Jordan (Hashemite Kingdom of) |
| K | |
| KAZ | Kazakhstan (Republic of) |
| KEN | Kenya (Republic of) |
| KGZ | Kyrgyz Republic |
| KIR | Kiribati (Republic of) |
| KOR | Korea (Republic of) |
| KRE | Democratic People's Republic of Korea |
| KWT | Kuwait (State of) |
| L | |
| LAO | Lao People's Democratic Republic |
| LBN | Lebanon |
| LBR | Liberia (Republic of) |
| LBY | Socialist People's Libyan Arab Jamahiriya |
| LCA | Saint Lucia |
| LIE | Liechtenstein (Principality of) |
| LSO | Lesotho (Kingdom of) |
| LTU | Lithuania (Republic of) |
| LUX | Luxembourg |
| LVA | Latvia (Republic of) |
| M | |
| MAU | Mauritius (Republic of) |
| MCO | Monaco (Principality of) |
| MDA | Moldova (Republic of) |
| MDG | Madagascar (Republic of) |
| MEX | Mexico |
| MHL | Marshall Islands (Republic of the) |
| MKD | Republic of Macedonia |
| MLA | Malaysia |
| MLD | Maldives (Republic of) |
| MLI | Mali (Republic of) |
| MLT | Malta |
| MNE | Montenegro (Republic of) |
| MNG | Mongolia |
| MOZ | Mozambique (Republic of) |
| MRC | Morocco (Kingdom of) |
| MTN | Mauritania (Islamic Republic of) |
| MWI | Malawi |
| N | |
| NCG | Nicaragua |
| NGR | Niger (Republic of the) |
| NIG | Nigeria (Federal Republic of) |
| NMB | Namibia (Republic of) |
| NOR | Norway |
| NPL | Nepal |
| NRU | Nauru (Republic of) |
| NZL | New Zealand |
| O | |
| OMA | Oman (Sultanate of) |
| P | |
| PAK | Pakistan (Islamic Republic of) |
| PHL | Philippines (Republic of the) |
| PNG | Papua New Guinea |
| PNR | Panama (Republic of) |
| POL | Poland (Republic of) |
| POR | Portugal |
| PRG | Paraguay (Republic of) |
| PRU | Peru |
| Q | |
| QAT | Qatar (State of) |
| R | |
| ROU | Romania |
| RRW | Rwandese Republic |
| RUS | Russian Federation |
| S | |
| S | Sweden |
| SDN | Sudan (Republic of the) |
| SEN | Senegal (Republic of) |
| SEY | Seychelles (Republic of) |
| SLM | Solomon Islands |
| SLV | El Salvador (Republic of) |
| SMO | Samoa (Independent State of) |
| SMR | San Marino (Republic of) |
| SNG | Singapore (Republic of) |
| SOM | Somali Democratic Republic |
| SRB | Serbia (Republic of) |
| SRL | Sierra Leone |
| STP | São Tomé and Príncipe (Democratic Republic of) |
| SUI | Switzerland (Confederation of) |
| SUR | Suriname (Republic of) |
| SVK | Slovakia |
| SVN | Slovenia (Republic of) |
| SWZ | Swaziland (Kingdom of) |
| SYR | Syrian Arab Republic |
| T | |
| TCD | Chad (Republic of) |
| TGO | Togolese Republic |
| THA | Thailand |
| TJK | Tajikistan (Republic of) |
| TKM | Turkmenistan |
| TON | Tonga (Kingdom of) |
| TRD | Trinidad and Tobago |
| TUN | Tunisia |
| TUR | Turkey |
| TUV | Tuvalu |
| TZA | Tanzania (United Republic of) |
| U | |
| UAE | United Arab Emirates |
| UGA | Uganda (Republic of) |
| UKR | Ukraine |
| URG | Uruguay (Eastern Republic of) |
| USA | United States of America |
| UZB | Uzbekistan (Republic of) |
| V | |
| VCT | Saint Vincent and the Grenadines |
| VEN | Venezuela (Bolivarian Republic of) |
| VTN | Vietnam (Socialist Republic of) |
| VUT | Vanuatu (Republic of) |
| Y | |
| YEM | Yemen (Republic of) |
| Z | |
| ZMB | Zambia (Republic of) |
| ZWE | Zimbabwe (Republic of) |
The ITU also designates the following codes for other areas around the world that are not member states.
Notes: