What was the official name of the document that formalized Japan’s 1945 capitulation?

The official document that formalized Japan’s 1945 capitulation was the Japanese Instrument of Surrender.

It was signed aboard USS Missouri in Tokyo Bay on 2 September 1945. The document recorded Japan’s acceptance of the terms set by the Allied powers and brought the war with Japan to a formal end.

The instrument was distinct from the Potsdam Declaration, which had been issued on 26 July as an Allied demand for Japan to surrender. It was also distinct from Hirohito’s radio broadcast on 15 August, which announced Japan’s decision to accept those terms.

The document was signed by Japanese representatives and by Allied representatives from nine nations. Its wording placed the authority of the Emperor and Japanese government under the Supreme Commander for the Allied Powers from the moment of surrender, establishing the framework for the occupation of Japan.