Nine Allied powers, excluding Japan, signed the 1945 Instrument of Surrender.
The signatories representing Allied powers were the United States, China, the United Kingdom, the Soviet Union, Australia, Canada, France, the Netherlands, and New Zealand. General Douglas MacArthur signed first for the Allied powers in his capacity as Supreme Commander, followed by the national representatives.
The Japanese delegation signed before the Allied representatives. Foreign Minister Mamoru Shigemitsu signed for the Emperor and the Japanese government, while General Yoshijiro Umezu signed for the Imperial General Headquarters. The structure of the document therefore recorded both Japan’s acceptance and the authority of the victorious coalition.
The number nine can be confusing because MacArthur’s signature appears separately from the national signatures, and because several Allied governments had different military commands in the Pacific. The count here refers to the nine represented Allied powers that signed after MacArthur during the ceremony aboard USS Missouri on September 2, 1945.