The Vietnamese cash, also called the sapek or sapèque, is a cast round coin with a square hole that was an official currency of Vietnam from the Đinh dynasty in 970 until the Nguyễn dynasty in 1945, and remained in circulation in North Vietnam until 1948. The same type of currency circulated in China, Japan, Korea, and Ryūkyū for centuries. Though the majority of Vietnamese cash coins throughout history were copper coins, lead, iron and zinc coins also circulated alongside them often at fluctuating rates. Coins made from metals of lower intrinsic value were introduced because of various superstitions involving Vietnamese people burying cash coins, as the problem of people burying cash coins became too much for the government. Almost all coins issued by government mints tended to be buried mere months after they had entered circulation. The Vietnamese government began issuing coins made from an alloy of zinc, lead, and tin. As these cash coins tended to be very fragile, they would decompose faster if buried, which caused the Vietnamese people to stop burying their coins.

The Đinh dynasty, officially Great Cồ Việt, was a Vietnamese dynasty. It was founded in 968 when Đinh Bộ Lĩnh vanquished the upheavals of Twelve warlords and ended when the son of Đinh Bộ Lĩnh, Đinh Toàn, ceded the throne to Lê Hoàn in 980.