A cash seal (simplified Chinese: ; traditional Chinese: ; pinyin: ; "Baochao" means "valuable money", "Yin" means "seal") is a type of seal used as an anti-counterfeiting measure on paper money or banknotes. The cash seal first appeared during the Song dynasty in China.
The short name is Chao Yin (simplified Chinese: ; traditional Chinese: ), and the full name is Seal of Baochao (simplified Chinese: ?; traditional Chinese: ?; pinyin: ), or Baochao Yinjian (simplified Chinese: ?; traditional Chinese: ?). The name can also be simply translated as "money seal" or "banknote seal".
The economy of China during the Song dynasty outpaced the supply of traditional coinage, leading the government to issue banknotes (Jiaozi ()) to increase the money supply. Subsequently, a government department was created to manage cash affairs, with its responsibilities including producing and issuing cash, and combating counterfeiting. The cash seal was developed as an anti-counterfeiting measure; official banknotes received a red, sometimes black or purple, stamp at their centres. This forced counterfeiters to attempt to replicate the seal, presumably leading to distinguishable lower quality stamps. Severe punishments, including the death penalty, were given counterfeiters.
The Ming also Qing dynasties also stamped banknotes. The Ming government department responsible for cash affairs and the use of the cash seal was the Baochao Bureau (simplified Chinese: ; traditional Chinese: ; pinyin: ).
The use of cash seals is no longer restricted to governments. Seals or private individuals and organizations may be used in the same manner on private banknotes to represent the parties' trust, credit, or authority.
In the era of the Republic of China, these seal stamps could also be called Yinhang Yin (/; direct translation: the seal stamp of bank, or just "bank seal").
In Japan, gink?-in (Japanese: ) seals have similar functions.
In ancient China: