What was the formal name of the 1945 agreement that legally recorded Japan’s surrender?

The formal name of the 1945 agreement that legally recorded Japan’s surrender was the Japanese Instrument of Surrender.

The instrument was signed aboard USS Missouri in Tokyo Bay on September 2, 1945. It recorded Japan’s acceptance of the terms set out by the Allied powers and required Japanese forces to cease hostilities and surrender. The document therefore marked the formal end of World War II fighting involving Japan.

It was not a peace treaty. A surrender instrument ends active hostilities by establishing capitulation, while a peace treaty settles the longer-term legal relationship between former enemies. Japan later signed the Treaty of San Francisco in 1951, which entered into force in 1952 and formally ended the state of war with most Allied countries.

The Potsdam Declaration was different again: it stated the conditions the Allies demanded for Japan’s surrender. The Cairo Declaration, issued in 1943, described Allied aims concerning Japan’s territorial disposition. These documents are connected, but they were not the same agreement.