honesty box       
noun [ C ] mainly UK uk/ˈɒn.ə.sti ˌbɒks/ us/ˈɑː.nə.sti ˌbɑːks/ (US usually honor box)
 诚实箱(当无人接收付款时,人们将钱放入其中作为收款箱的容器)
a container into which people are asked to put money as payment for something, when there is no one available to take the payment
  The grounds are open to the public; inside the gate is an honesty box and a map.  庭院向公众开放:大门内有一个诚实箱和地图。 
 The store includes "Honesty boxes" where customers can pay for newspapers without having to queue. 该商店提供了“诚实付款箱”,顾客无需排队即可购买报纸。 
 - More examples
 - Next to the coffee machine is an honesty box into which we are requested to put 30p.
 - The gardens are open daily all year round from 9am until sunset; an honesty box is provided for admission (£2).
 - We have introduced honesty boxes, and people who use the huts are asked to pay a small fee.
 - I used to sell the eggs—we didn't have a proper shop; I just left an honesty box for people to put the money into.
 - They offered fans an "honesty box" approach to their last album, allowing a free download in exchange for a fee chosen by the downloader.