The working paper aims to diagnose Brexit’s impact on the taxation of Polish-British commercial exchange. This research problem determined in such a way is considered from the point of view of the possible legislative consequences as well as the application of provisions regulating the structural elements of border taxes. The author formulated the thesis that the exit of the United Kingdom from the European Union will be an event that will significantly affect the changes in tax and customs qualification of the exchange of goods between Poland and that country.