What was the formal name of the document signed aboard USS Missouri on September 2, 1945?

The formal name of the document signed aboard USS Missouri was the Japanese Instrument of Surrender.

This instrument was the legal document that recorded Japan’s capitulation and brought the war with the Allied powers to an official close. It required Japan to accept the terms of the Potsdam Declaration and ordered Japanese forces to cease resistance and surrender.

The document was signed in Tokyo Bay on September 2, 1945. Japan’s foreign minister Mamoru Shigemitsu signed for the Japanese government, while General Yoshijirō Umezu signed for Imperial General Headquarters. Allied representatives then added their signatures.

It is often confused with the Potsdam Declaration, but the two documents served different purposes. The Potsdam Declaration, issued in July 1945, stated the Allies’ terms and demanded Japan’s surrender. The Instrument of Surrender recorded Japan’s acceptance of those terms.