This article examines the interactions between two distinct currency systems that dominated the Deccan during the period c. 1350–1687—that of the Bahmani sultanate and its successor states, and that of the Vijayanagara kingdom and its successors. Based on a GIS database of over 300 reported coin hoards containing material issued by either state, the study demonstrates that while the Bahmani currency was limited in circulation to Bahmani territory, the coinage of Vijayanagara in contrast enjoyed wide circulation throughout the entire Deccan region. This was evidently due to a high demand in rural areas for the small, conveniently-sized gold coins of Vijayanagara known as hon, since gold coins of similar weight, purity and fabric had customarily been used throughout the Deccan to pay agricultural taxes since the late tenth century. By the opening years of the sixteenth century, agricultural and commercial taxes within the Bahmani territory were being assessed and collected in Vijayanagara-issued hons. The Vijayanagara hon circulated in such great numbers in Bahmani territory that it became an integral part of the economy of the Bahmanis and their successors, prompting Firishta to note (in 1607 CE) that ‘even up to the present day, that same infidel coinage is current among the Muslims’.