Most comprehensive and up-to-date information about Latvian customs legislation, regulations, and tariffs is published by a private company KOMIN . Trade and Customs regarding Latvia Since Latvia has joined the E.U., the aquis commaunitaire has been adopted, although certain transitional rules remain in place and the process of practical implementation may still be deficient in some areas. For both investors and merchants, Latvia has become part of the European Taxation and Customs Union as part of the Single Market. Trade with member states is subject to EU and implementing domestic legislation only, while trade with countries outside the EU has come under a largely new regime defined by EU legislation and treaties.