The koruna, or crown (sign: Kč; code: CZK, Czech: koruna česká), has been the currency of the Czech Republic since 1993. The koruna is one of the European Union's seven currencies, and the Czech Republic is legally bound to adopt the euro once it satisfies the convergence criteria. The official name in Czech is koruna česká (plural koruny české, though the zero-suffixed genitive plural form korun českých is used on banknotes and coins of value 5 Kč or higher). The ISO 4217 code is CZK and the local acronym is Kč, which is placed after the numeric value (e.g., "50 Kč") or sometimes before it (as is seen on the 10-koruna coin). One crown is made up of 100 hellers (abbreviated as "h", official name in Czech: singular: haléř, nominative plural: haléře, genitive plural: haléřů – used with numbers higher or equal to 5 – e.g. 3 haléře, 8 haléřů), but hellers have now been withdrawn from circulation, and the smallest unit of physical currency is 1 Kč.