The organized and controlled form of collecting consumption taxes and toll from the import and export trade goes back to the 17th century in Sweden. The customs administration and procedure were regulated by royal announcements, and the majority of the documents found in the customs archives represent thus records stipulated by such notifications. The customs archives can be used for research on several levels; the announcements reflect currents within both the domestic and foreign politics, while the account lists for financial statistics portray the extent of the trade. The various lists of compilation can be further used to follow for instance the development of different units of measurement, the expansion of tax rates, the value of trade goods or the changes in monetary units or systems. The diaries, architectural plans of the customs offices and maps of the toll areas place the customs officials and their work within the local scenery. The thesis focuses on archives deriving from customs located at harbors and on the Swedish-Norwegian border in the county of Dalarna. Examples of documents originating from the collection of agricultural tariffs have been included, as well as cases from a tariff court (accisrätt). These selected archives cover both the different kinds and levels of customs administration found in Sweden from the 17 the century and onward. This is a one year master’s thesis in Archival Science.