Customs books are the primary source for studying the history of domestic and foreign trade in Russia during the 17th and the 1st half of the 18th centuries. However, these documents have been preserved unevenly geographically and chronologically. The absence of customs books can be partially compensated by customs statements, which provide personal information about merchants along with details regarding their shipments, including points of departure and destination. The Russian State Archive of Ancient Acts houses 136 extracts from the Kursk Border Customs, which were forwarded to it from customs offices in other cities. An analysis of these documents reveals the geography of trade relations involving Kursk, one of the foremost economic centers in southern European Russia during the early to mid-18th century. The results not only clarify Kursk’s significance in the system of interregional trade relations but al so underscore the potential of customs statements as a valuable source for studying trade history. This analysis examines the geographical distribution of merchants who received statements, their travel routes, and the range of goods transported. The customs records indicate a notable expansion of the geography of Kursk’s trade relations by the early 1740s compared to the 17th century and the first two decades of the 18th century. Particularly noteworthy is the emergence of an eastern trade route passing through Kursk, highlighting the ongoing development of a unified All-Russian market.