Upon landing on 29 September 1914, the Japanese naval officers broke into the post office, confiscated all German stamp stock that could be found, first demonetized it and then destroyed it. All mail was handled by the naval authorities.[2].

There are no formal records of Japanese overprints of German stamps, nor are there formal records of special Japanese issues. It seems that normal letters on Jaluit were taken to the post office, handed to a censor and sent without stamps after payment of the delivery fee.[3]. Overseas mail was handled in a similar fashion. The letter was sent via naval vessel to a naval base and there handed to civilian posal authorities. Examples of a letter from Jaluit to England are known which show a Japanese stamp and registration label, both cancelled in Kobe.[4].

Contemporary (1915) items in the Australian philatelic press mention that overprinted stamps were in existence, but that these had been created by the Japanese commander, the Japanese paymaster and the Japanese navy physician as curiosities, overprinting the stamps with their own personal seal.[6]. These items were created on demand for local collectors and must be regarded as bogus stamps, which are of historical, but no formal philatelic value. Known are the uses of the chops of Commander Tashikawa, Lieutenant Kobayashi and Paymaster K. Tanura. The contemporray stamp dealers offered overprints with chops by three different officers.[7] ]

Yet at the same time, Australian stamp dealers rushed to obatin suplies of these overprinted stamps, and advertised them in the collectors' journals. A set comprised of 3, 5, 10, 20, 25, 30, 50 and 80 Pfennig values sold for £4 per set. [8]

A number of genuine covers are known. While few date to the Japanese Naval Administration Period (1914-1922), most date to the period of the Japanese Mandate of the League of Nations (1918-1937 [1945]).

From other occupied areas, such as the Carolines other postal courtesy cancellations are known, such as a German Caroline Islands 25Pfg cancelled with a Japanese postal seal.[13] .

Shown at left is an item that reputedly portrays a stamp used in the Caroline Islands during the Japanese occupation. This is most likely a fradulent creation using a genuine stamp and a type-writer. It is very probable that similar creations have also been made for the Marshall Islands.