The U.K. Office of Public Sector Information (OPSI) is responsible for the operation of Her Majesty's Stationery Office (usually abbreviated as HMSO) and of other public information services in the United Kingdom. Since October 2006, OPSI has been part of The National Archives of the United Kingdom.
It sets standards for the implementation of information policy. It encourages access to and re-use of government information. OPSI is responsible for the Information Fair Trader Scheme (IFTS) to encourage openness in government and assist re-use of public sector information. It also investigates complaints made by those seeking to re-use government information.
OPSI also manages the Crown copyright.