The different nations that authorize or license radio stations are assigned, by international agreement, a set of unique call sign prefixes to help identify where a station is located and under which national authority the station is operating. As a result, these prefixes can be a big aid in determining where a station you're hearing is located.

Call sign prefixes are not an infallible way to determine a station's location, however. A shipboard station will use the call letters assigned to it by its home nation regardless of where it is operating from. A nation's call sign allocations are also used for its territories and possessions, no matter how remote from the nation.

  Some stations in the former Soviet Union use their "traditional" call signs despite being located in a now-independent republic with different allocations. Many military stations use "tactical" call signs that follow no set allocations or rules. However, most ham radio, broadcasting, and maritime stations will have their call signs assigned in accordance with the list on this page.

Note that no official call signs use the QAA-QZZ block. These are reserved for international radiotelegraph "Q-signals." The most common Q-signals are in Radio Regulations section.

The allocations in the following list are in alphanumeric order:

AAA-ALZ: United States

AMA-AOZ: Spain

APA-ASZ: Pakistan

ATA-AWZ: India

AXA-AXZ: Australia

AYA-AZZ: Argentina

A2A-A2Z: Botswana

A3A-A3Z: Tonga

A4A-A4Z: Oman

A5A-A5Z: Bhutan

A6A-A6Z: United Arab Emirates

A7A-A7Z: Qatar

A8A-A8Z: Liberia

A9A-A9Z: Bahrain

BAA-BZZ: China (BVA-BVZ used by Taiwan)

CAA-CEZ: Chile

CFA-CKZ: Canada

CLA-CMZ: Cuba

CNA-CNZ: Morocco

COA-COZ: Cuba

CPA-CPZ: Bolivia

CQA-CUZ: Portugal

CVA-CXA: Uruguay

CYA-CZZ: Canada

C2A-C2Z: Nauru

C3A-C3Z: Andorra

C4A-C4Z: Cyprus

C5A-C5Z: The Gambia

C6A-C6Z: Bahamas

C7A-C7Z: World Meteorological Organization

C8A-C9Z: Mozambique

DAA-DRZ: Germany

DSA-DTZ: South Korea

DUA-DZZ: Philippines

D2A-D3Z: Angola

D4A-D4Z: Cape Verde Islands

D5A-D5Z: Liberia

D6A-D6Z: Comoros

D7A-D9Z: South Korea

EAA-EHZ: Spain

EIA-EJZ: Ireland

EKA-EKZ: Armenia

ELA-ELZ: Liberia

EMA-EOZ: Ukraine

EPA-EQZ: Iran

ERA-ERZ: Moldova

ESA-ESZ: Estonia

ETA-ETZ: Ethiopia

EUA-EWZ: Belarus

EXA-EXZ: Kyrgyzstan

EYA-EYZ: Tajikistan

EZA-EZZ: Turkmenistan

E2A-E2Z: Thailand

E3A-E3Z: Eritrea

E4A-E4Z: Palestine

E5A-E9Z: Not allocated

FAA-FZZ: France

GAA-GZZ: Great Britain

HAA-HAZ: Hungary

HBA-HBZ: Switzerland

HCA-HDZ: Ecuador

HEA-HEZ: Switzerland

HFA-HFZ: Poland

HGA-HGZ: Hungary

HHA-HHZ: Haiti

HIA-HIZ: Dominican Republic

HJA-HKZ: Colombia

HLA-HLZ: South Korea

HMA-HMZ: North Korea

HNA-HNZ: Iraq

HOA-HPZ: Panama

HQA-HRZ: Honduras

HSA-HSZ: Thailand

HTA-HTZ: Nicaragua

HUA-HUZ: El Salvador

HVA-HVZ: Vatican City

HWA-HWZ: France

HZA-HZZ: Saudi Arabia

H2A-H2Z: Cyprus

H3A-H3Z: Panama

H4A-H4Z: Solomon Islands

H6A-H7Z: Nicaragua

H8A-H9Z: Panama

IAA-IZZ: Italy

JAA-JSZ: Japan

JTA-JVZ: Mongolia

JWA-JXZ: Norway

JYA-JYZ: Jordan

JZA-JZZ: Indonesia

J2A-J2Z: Djibouti

J3A-J3Z: Grenada

J4A-J4Z: Greece

J5A-J5Z: Guinea-Bissau

J6A-J6Z: St. Lucia

J7A-J7Z: Dominica

J8A-J8Z: St. Vincent

J9A-J9Z: Not allocated

KAA-KZZ: United States

LAA-LNZ: Norway

LOA-LWZ: Argentina

LXA-LXZ: Luxembourg

LYA-LYZ: Lithuania

LZA-LZZ: Bulgaria

L2A-L9Z: Argentina

MAA-MZZ: Great Britain

NAA-NZZ: United States

OAA-OCZ: Peru

ODA-ODZ: Lebanon

OEA-OEZ: Austria

OFA-OJZ: Finland

OKA-OLZ: Czech Republic

OMA-OMZ: Slovak Republic

ONA-OTZ: Belgium

OUA-OZZ: Denmark

O2A-O9Z: Not allocated

PAA-PIZ: Netherlands

PJA-PJZ: Netherlands Antilles

PKA-POZ: Indonesia

PPA-PYZ: Brazil

PZA-PZZ: Surinam

P2A-P2Z: Papua New Guinea

P3A-P3Z: Cyprus

P4A-P4Z: Aruba

P5A-P9Z: North Korea

QAA-QZZ: Service Abbreviations

RAA-RZZ: Russia

SAA-SMZ: Sweden

SNA-SRZ: Poland

SSA-SSM: Egypt

SSN-STZ: Sudan

SUA-SUZ: Egypt

SVA-SZZ: Greece

S2A-S3Z: Bangladesh

S5A-S5Z: Slovenia

S6A-S6Z: Singapore

S7A-S7Z: Seychelles

S8A-S8Z: South Africa

S9A-S9Z: Sao Tome e Principe

TAA-TCZ: Turkey

TDA-TDZ: Guatemala

TEA-TEZ: Costa Rica

TFA-TFZ: Iceland

TGA-TGZ: Guatemala

THA-THZ: France

TIA-TIZ: Costa Rica

TJA-TJZ: Cameroon

TKA-TKZ: France

TLA-TLZ: Central African Republic

TMA-TMZ: France

TNA-TNZ: Congo

TOA-TQZ: France

TRA-TRZ: Gabon

TSA-TSZ: Tunisia

TTA-TTZ: Chad

TUA-TUZ: Cote d'Ivoire

TVA-TXZ: France

TYA-TYZ: Benin

TZA-TZZ: Mali

T2A-T2Z: Tuvalu

T3A-T3Z: Kiribati

T4A-T4Z: Cuba

T5A-T5Z: Somalia

T6A-T6Z: Afghanistan

T7A-T7Z: San Marino

T8A-T8Z: Palau

T9A-T9Z: Bosnia-Herzegovina

UAA-UIZ: Russia

UJA-UMZ: Uzbekistan

UNA-UQZ: Kazakhstan

URA-UZZ: Ukraine

VAA-VGZ: Canada

VHA-VNZ: Australia

VOA-VOZ: Canada

VPA-VQZ: Great Britain

VRA-VRZ: China

VSA-VSZ: Great Britain

VTA-VWZ: India

VXA-VYZ: Canada

VY0: Territory of Nunavut, Canada

VZA-VZZ: Australia

V2A-V2Z: Antigua and Barbuda

V3A-V3Z: Belize

V4A-V4Z: St. Kitts and Nevis

V5A-V5Z: Namibia

V6A-V6Z: Micronesia

V7A-V7Z: Marshall Islands

V8A-V8Z: Brunei

V9A-V9Z: Not allocated

WAA-WZZ: United States

XAA-XIZ: Mexico

XJA-XOZ: Canada

XPA-XPZ: Denmark

XQA-XRZ: Chile

XSA-XSZ: China

XTA-XTZ: Burkina Faso

XUA-XUZ: Cambodia

XVA-XVZ: Vietnam

XWA-XWZ: Laos

XXA-XXZ: Portugal

XYA-XZZ: Myanmar

X2A-X9Z: Not allocated

YAA-YAZ: Afghanistan

YBA-YHZ: Indonesia

YIA-YIZ: Iraq

YJA-YJZ: Vanuatu

YKA-YKZ: Syria

YLA-YLZ: Latvia

YMA-YMZ: Turkey

YNA-YNZ: Nicaragua

YOA-YRZ: Romania

YSA-YSZ: El Salvador

YTA-YUZ: Yugoslavia

YVA-YVZ: Venezuela

YV0: Aves Island, Venezuela

YZA-YZZ: Yugoslavia

Y2A-Y9Z: Germany

ZAA-ZAZ: Albania

ZBA-ZJZ: Great Britain

ZKA-ZMZ: New Zealand

ZNA-ZOZ: Great Britain

ZPA-ZPZ: Paraguay

ZQA-ZQZ: Great Britain

ZRA-ZUZ: South Africa

ZVA-ZVZ: Brazil

Z2A-Z2Z: Zimbabwe

Z3A-Z3Z: Macedonia

Z4A-Z9Z: Not allocated

1AA-1ZZ: Not allocated; unofficially used in disputed territories

2AA-2ZZ: Great Britain

3AA-3AZ: Monaco

3BA-3BZ: Mauritius

3CA-3CZ: Equatorial Guinea

3DA-3DM: Swaziland

3DN-3DZ: Fiji

3EA-3FZ: Panama

3GA-3GZ: Chile

3HA-3UZ: China

3VA-3VZ: Tunisia

3WA-3WZ: Vietnam

3XA-3XZ: Guinea

3YA-3YZ: Norway

3ZA-3ZZ: Poland

4AA-4CZ: Mexico

4DA-4IZ: Philippines

4JA-4KZ: Azerbaijan

4LA-4LZ: Georgia

4MA-4MZ: Venezuela

4NA-4OZ: Yugoslavia

4PA-4SZ: Sri Lanka

4TA-4TZ: Peru

4UA-4UZ: United Nations

4VA-4VZ: Haiti

4WA-4WZ: East Timor

4YA-4YZ: International Civil Aviation Organization

4XA-4XZ: Israel

4ZA-4ZZ: Israel

5AA-5AZ: Libya

5BA-5BZ: Cyprus

5CA-5GZ: Morocco

5HA-5IZ: Tanzania

5JA-5KZ: Colombia

5LA-5MZ: Liberia

5NA-5OZ: Nigeria

5PA-5QZ: Denmark

5RA-5SZ: Madagascar

5TA-5TZ: Mauritania

5UA-5UZ: Niger

5VA-5VZ: Togo

5WA-5WZ: Western Samoa

5XA-5XZ: Uganda

5YA-5ZZ: Kenya

6AA-6BZ: Egypt

6CA-6CZ: Syria

6DA-6JZ: Mexico

6KA-6NZ: South Korea

6OA-6OZ: Somalia

6PA-6SZ: Pakistan

6TA-6UZ: Sudan

6VA-6WZ: Senegal

6XA-6XZ: Madagascar

6YA-6YZ: Jamaica

6ZA-6ZZ: Liberia

7AA-7IZ: Indonesia

7JA-7NZ: Japan

7OA-7OZ: Yemen

7PA-7PZ: Lesotho

7QA-7QZ: Malawi

7RA-7RZ: Algeria

7SA-7SZ: Sweden

7TA-7YZ: Algeria

7ZA-7ZZ: Saudi Arabia

8AA-8IZ: Indonesia

8JA-8NZ: Japan

8OA-8OZ: Botswana

8PA-8PZ: Barbados

8QA-8QZ: Maldives

8RA-8RZ: Guyana

8SA-8SZ: Sweden

8TA-8YZ: India

8ZA-8ZZ: Saudi Arabia

9AA-9AZ: Croatia

9BA-9DZ: Iran

9EA-9FZ: Ethiopia

9GA-9GZ: Ghana

9HA-9HZ: Malta

9IA-9JZ: Zambia

9KA-9KZ: Kuwait

9LA-9LZ: Sierra Leone

9MA-9MZ: Malaysia

9NA-9NZ: Nepal

9OA-9TZ: Zaire

9UA-9UZ: Burundi

9VA-9VZ: Singapore

9WA-9WZ: Malaysia

9XA-9XZ: Rwanda

9YA-9ZZ: Trinidad and Tobago