The United Kingdom is home to a large number of private military and security companies operating both domestically and abroad, and the UK Ministry of Defence (MoD), Foreign and Commonwealth Office (FCO) and Department for International Development (DFID) have increasingly relied on PMSCs providing logistics and armed security. Domestic security companies are governed primarily through the 2001 Private Security Act and its accompanying subsidiary regulation. By contrast, while the regulation of firms operating abroad has been discussed since the publication of a 2002 FCO Green Paper, the international activities of British PMSCs are not formally regulated. Due to the international scope of UK PMSCs operations, the UK government has discarded the possibility of enforcing restrictive domestic legislation, opting for a self-regulatory approach based on the signing of domestic and  international third-party monitored codes of conduct and the use of government demand as an informal incentive for high standards of behavior. 

The growth of the UK maritime private security industry has recently brought to the fore a new governmental actor in the regulatory process, namely the Department for Transport (DfT). In late 2011, the DfT has authorized the use of private security on UK flagged vessels transiting through the area between Suez and the Straights of Hormuz. Under the current regulatory framework, UK vessels transiting through the high risk area will have to require authorization from the Home Office for the possession of firearms.