Historical records and releases

Last Updated: 28 Apr 2016
The Public Records Act 1958 requires government departments to transfer records to the National Archives 30 years after creation. GCHQ has a blanket exemption from this requirement, but has made voluntary releases which appear on the National Archives catalogue under the HW series.

Release of Bletchley Park and other GC&CS records

By 2004 most of the surviving records of the Government Code and Cipher School (GC&CS) had been released, following a 10-year review exercise. These records date from the beginnings of GC&CS in 1919 until VJ Day (16 August 1945), and include all wartime activity carried out from Bletchley Park. This means that virtually all surviving SIGINT or SIGINT-related records from this period have been made available for public access, regardless of subject or target.

Release of post-war historical records

Series HW 15 contains records relating to VENONA, reporting on the activities of Soviet intelligence between 1942 and 1948, complementing a release made by the National Security Agency in the United States.

Work is currently underway to review and release GCHQ intelligence reports dating from the early Cold war period, 1945-1950, on the Soviet Bloc countries, Albania, Bulgaria, Czechoslovakia, Hungary, Poland, Romania, USSR and Yugoslavia (series HW 75).