An amateur radio callsign is a unique identifier assigned to a licensed amateur radio operator by their national telecommunications authority. It consists of a prefix (indicating the country), a numeral (often indicating a region within the country), and a suffix. For example, in K1ABC, "K" is the US prefix, "1" indicates the New England region, and "ABC" is the operator's unique suffix.

The International Telecommunication Union (ITU) allocates blocks of callsign prefixes to each country. These allocations are published in the ITU Radio Regulations. Each country's regulator then assigns specific callsigns within their allocated blocks. Prefixes can range from a single letter (like K for the USA) to multiple characters including numbers (like 2E0 for the United Kingdom).

The ITU divides the world into three regions for frequency allocation purposes: Region 1 (Europe, Africa, Middle East, Northern Asia), Region 2 (the Americas), and Region 3 (Asia-Pacific, Oceania). Knowing the ITU region helps operators understand which frequency bands and operating modes are permitted in a given location.

CQ zones are a system of 40 geographic zones used primarily for contesting and award programs like the CQ Worked All Zones (WAZ) award. They differ from ITU regions in being more granular. For example, the continental United States spans CQ zones 3, 4, and 5, while Alaska is in zone 1 and Hawaii in zone 31.

Generally, no. The ITU allocates unique prefix blocks to each country to avoid confusion. However, some prefixes may change over time due to geopolitical changes (e.g., the former Soviet Union's prefixes were redistributed). Occasionally, special event stations may use unique or temporary prefixes, but these are coordinated to prevent conflicts.

The numeral (or numerals) in a callsign typically represents a geographic subdivision within the country. For example, in the US, the number indicates one of 10 call districts (1=New England, 6=California, etc.). In the UK, "G1" vs "G7" can indicate the license class. Some countries use the number purely as part of the unique identifier without geographic meaning.

No. A callsign is tied to the issuing country's licensing authority. If you move to another country, you must obtain a new license and callsign from that country's regulator. However, many countries have reciprocal operating agreements (like CEPT in Europe) that allow visiting operators to use their home callsign with a local prefix appended (e.g., a US operator in France might operate as F/K1ABC).

This tool uses a comprehensive database of 250+ ITU-allocated prefixes covering virtually all countries and major territories worldwide. It matches the longest possible prefix from your input callsign. While extremely accurate for standard callsigns, rare edge cases (very obscure territories, recently changed prefixes, or special event callsigns) may occasionally not match perfectly. We update the database regularly.

The prefix is the beginning portion of a callsign that identifies the country (e.g., "VE" for Canada, "G" for the UK). The full callsign includes the prefix, a numeral, and a unique suffix (e.g., "VE3XYZ"). This tool extracts the prefix from your full callsign to identify the country of origin. You can enter either just a prefix or a complete callsign.