This series consists of digitized copies of official documents of adherence to the UNESCO Constitution by UNESCO Member States, known as ratification instruments, dating from the establishment of the Organization in 1945 up to the most recent ratifications. The original documents are physically held in the UK National Archives in Kew.

Since the establishment of UNESCO on 16 November 1945 during the Conference for the Establishment of UNESCO, held at the Institute of Civil Engineers in London, UNESCO’s original Constitution, along with every formal acceptance of the Constitution by Member States, have been deposited in the UK Foreign Office. The documents are transferred by the UK Foreign Office in London to the UK National Archives in Kew, which currently still holds them. UNESCO in Paris is notified by the UK Foreign Office of the deposit of each ratification document.

From 2020 to 2021, to mark UNESCO’s 75th anniversary, the UK National Commission for UNESCO, the UK Permanent Delegation to UNESCO, the UK Department for Digital, Culture, Media and Sport, and the UNESCO Archives worked with the UK National Archives to digitize each UNESCO Member State ratification instrument. The digitization of the documents was funded by the UK Department for Digital, Culture, Media and Sport.