What was the formal name of the document that legally ended Japan’s war with the Allies?

The formal document that ended Japan’s war with the Allies was the Japanese Instrument of Surrender.

Representatives signed it aboard USS Missouri in Tokyo Bay on September 2, 1945. The document stated that Japan accepted the provisions of the Potsdam Declaration and ordered the unconditional surrender of Japanese armed forces. It took effect at approximately 9:25 a.m. Japan Standard Time.

The instrument was not the same as the Potsdam Declaration. The declaration was an Allied demand issued on July 26, 1945, while the instrument recorded Japan’s formal capitulation. It was also not the Treaty of San Francisco, which later established the legal framework for ending the Allied occupation and restoring Japan’s sovereignty in 1952.

Japan and representatives of nine Allied governments signed the instrument. Regional surrender documents followed in places including China, the Philippines, Korea, and Southeast Asia as Japanese forces laid down their arms across the former empire.