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Press Release | June 24, 2010

Declassified UKUSA Signals Intelligence Agreement Documents Available

Today,  the United Kingdom's Government Communications Headquarters (GCHQ) and the National Security Agency/Central Security Service (NSA/CSS) are making publicly available declassified intelligence documents relating to the UKUSA (pronounced "Eu-Koo-SA") Agreement made between Great Britain and the United States. These declassified documents cover the period 1940-1956 and are available on the NSA website and the UK National Archives website.

The UKUSA agreement,  first called the BRUSA Agreement,  was signed in March 1946 and continues to serve as the foundation for cooperation in signals intelligence between the two nations. The agreement was later extended to encompass former British Dominions: Canada (1948),  Australia and New Zealand (1956). Collaboration in various areas of critical intelligence between each of the five partner-nations continues to the present day.

The released information includes:

  • the United Kingdom-United States of America (UKUSA) Agreement;
  • documents leading up to the formal start of the Agreement;
  • appendices; and,
  • annexes with periodic revisions.

For more information about the UKUSA Agreement Release,  please contact the NSA/CSS Public and Media Affairs Office at or by phone at 301-688-6524. For information on other declassified documents,  visit