Cash on the nail and cash on the barrelhead are two idioms that mean the same thing but come from very different sources. We will examine the definitions of cash on the nail and cash on the barrelhead, where these terms came from, where they are used, and some examples of that use in sentences.
Cash on the nail is a British idiom that means immediate payment, payment without any delay. The term cash on the nail is derived from an Anglo-Norman phrase, payer sur le ungle , which means immediate payment in full. The word ungle is derived from the Latin word unguis, which means fingernail or toenail. Literally, the term means to pay from one’s fingernail. This has eventually been shortened to cash on the nail.
Cash on the barrelhead, or sometimes cash on the barrel, is an American idiom that means immediate payment, payment without any delay. The term cash on the barrelhead or cash on the barrel is most probably derived from the fact that many transactions on the frontier, in general stores or in saloons took place over upended barrels used as tables. Note that barrelhead is properly rendered as one word.
A brutally tough wartime U.S. administration required Britain to pay cash on the nail for every ton of arms shipped across the Atlantic to assist our lonely struggle for survival. (The Daily Mail)
That “goes to show that most fliers will forgive and forget if you back apologies with cash on the barrel.” (USA Today)