The United Kingdom's intelligence machinery comprises:
Other parts of Government also contribute to intelligence collection and/or analysis and assessment: for example, the Serious Organised Crime Agency (SOCA) [External website], Her Majesty's Revenue and Customs (HMRC) [External website] and Home Office[External website].
SIS, Security Service and GCHQ - collectively known as the Agencies - were not publicly acknowledged for much of their existence. The SIS and Security Service originated in 1909, while there has been an official codebreaker since the 16th century. Their low profile has led to the proliferation of many rumours, myths and false impressions about their work and roles. Since the late 1980s, however, all three of the Agencies have been publicly acknowledged. They are now more open and accountable than at any previous point in their histories.
The operations and functions of the three Agencies are firmly rooted in legislation (see The Legislative Framework for the Agencies). Their funding is provided by a single account approved by Parliament, the Single Intelligence Account (SIA) - see Funding.
In 2009, the Prime Minister, on the advice of the Cabinet Secretary, with the support of the three Agency heads and having consulted widely within Government, agreed to the recommendations of an internal review on strengthening the central intelligence machinery. The review can be read here [PDF 15 pages 240KB]. The review built on the changes to the central intelligence machinery announced by the Prime Minister in July 2007. One outcome of the review was a revision to the terms of reference of the Joint Intelligence Committee, building on the improvements in this regard since Lord Butler’s 2004 report. The new terms of reference are available here.