This article briefly looks at the concept of legal tender, drawing on the experience of New Zealand’s recent change-over to new, lighter coins. Legal tender is a tender of payment that, by law, cannot effectively be refused in settlement of a debt denominated in the same currency. Although the basis for most cash transactions is generally taken for granted, the article notes that without the concept of legal tender, cash transactions could not always take place with sufficient certainty to satisfy the needs of consumers and sellers.