imprest system
noun [ C, usually singular ] business, finance & economics specialized uk/ˈɪmprest ˌsɪstəm/ us/ˈɪmprest ˌsɪstəm/
（商业机构保持一定资金用于零星开支的）定额预付制
a method of keeping an amount of cash in a business for paying small amounts, where a certain amount of money is kept and replaced to the same level at the beginning of each new period