In 820, Kamonryo was formed by integrating Kanimori no Tsukasa (Housekeeping Office) of Okurasho (Ministry of the Treasury) with Uchi no Kanimori no Tsukasa (Inner House Keeping Office) of Kunaisho (Ministry of the Sovereign's Household) both of which had the same official duties, as a part of administrative reforms.
掃部寮は弘仁11年（820年）に行政改革の一環として職掌の同じ大蔵省律令制における大蔵省掃部司と宮内省内掃部司が統合されて成立した。