Amateur radio call signs are allocated to amateur radio operators around the world. The call signs are used to legally identify the station or operator, with some countries requiring the station call sign to always be used and others allowing the operator call sign instead.

The International Telecommunication Union (ITU) allocates call sign prefixes for amateur radio callsigns, also known as a country code.

There are over 300 different country prefixes or codes used by amateur radio operators world wide.

The amateur radio call sign prefix for Australia is "VK". This is followed by a number which indicates the location of the amateur radio station;

VK1 - Australian Capital Territory
VK2 - New South Wales
VK3 - Victoria
VK4 - Queensland
VK5 - South Australia
VK6 - Western Australia
VK7 - Tasmania
VK8 - Northern Territory
VK9 - external territories e.g. Norfolk Island
VK0 - Antarctica

Following is a sample list of country call sign prefixes used by amateur radio operators;

Japan JA to JS Brazil PP to PY, ZV to ZZ
USA AA to AL, KA to KZ, NA to NZ, WA to WZ Italy IA to IZ
Thailand E2A to E2Z, HSA to HSZ Indonesia 7A to 7I, 8A to 8I, JZ, PK to PO, YB to YH
Korea 6K to 6N, D7 to D9, HL, DS & DT France FA to FZ, HW to HY, TH to TX
Germany DA to DR, Y2 to Y9 Ukraine EM to EO, UR to UZ
New Zealand ZL, ZK & ZM Argentina AY to AZ, L2 to L9, LO to LW
Spain AM to AO, EA to EH Poland 3Z, HF, SN to SR
United Kingdom 2A to 2Z, GA to GZ, MA to MZ, Australia VK0 to VK9
Canada CF to CZ, VA to VZ, XJ to XO Netherlands PJ
Russia RA to RZ, UA to UI Sweden 7S, 8S, SA to SM
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