The introduction, on the 1 January 1999, of the new common currency in the member states of the Economic and Monetary Union had to be preceded by the creation of the appropriate legal infrastructure, in terms of both primary and secondary sources of Union law. The euro regulations are precursory, as there is no previous history of a common currency acting as both unit of account in non-cash settlements and legal tender.

General issues pertaining to the establishment of the monetary union are covered by the European Union Treaty of February 7, 1992, which amends and supplements the Rome Treaty on the EEC with a view to the Economic and Monetary Union. The provisions of the EU Treaty regulate euro issues in a broad way and provide a basis for specific regulations (the executory acts). The key of those include: Council Regulation on certain provisions relating to the introduction of the euro No. 1103/97 of 17 June 1997 (popularly termed "Euroregulation I") as well as Council Regulation No. 974/98/WE of May 3, 1998 on the introduction of the euro (called "Euroregulation II").Those regulations concern primarily the so-called transition period, that is the period between 1 January 1999 and 31 December 2001. During this period, both national currencies and the euro will be in use in the EMU market. To guarantee the transparency and security of the law at the dual circulation stage, specific rules have been elaborated, such as that of legal equivalence of the euro and national currencies, of the continuity of legal provisions and contracts, rules concerning the determination of the value of payments and their execution in trade relations, currency conversion to the euro and procedures for rounding up amounts.

The above principles are considered to be of such significance to the continued transparency of the law that they have been adopted at the Community level. Union regulation has also been passed on technical aspects of euro currency issue, namely Regulation No. 975/98/WE of 31 December 1998 on denominations and technical specifications of euro coins to be launched - as well as issues relating to exchange rates: Regulations No. 2866/98 of 3 May 1998 regarding euro exchange rates against the national currencies of the countries introducing the new currency. While basic problems linked to the euro have already been regulated, de lege ferenda postulates include provisions concerning crime against the new currency (a framework regulation was admittedly passed in May 2000, tightening penalties for money counterfeiting).

The key issues of euro launch, regulated at the Union level, are of jus cogens nature. Some member countries have integrated the relevant Union laws into their national systems. In Germany, for example, the basic acts include the Act on the Introduction of the Euro of 9 June, 1998 and the Ministry of Finance Regulation of 28 April 1997: The Introduction of the Euro to the Legislation and Public Administration. They deal primarily with problems of discount rates, consequences of a joint currency to the law enforcement system, company law, accounting law, liabilities and debt convergence.

The introduction of a joint currency in the Economic and Monetary Union has created the need to adjust the relevant elements of the Polish law. The issues regulated so far include - pursuant to Art. 30 of Foreign Exchange Law of 18 December 1998 - the automatic conversion of the ECU to the euro as well as, partially, the principle of continuity of law provisions and contracts. Another act passed in connection with the euro is the Regulation of the President of the National Bank of Poland No. 21/98 of 31 December 1998 concerning the list of convertible currencies. Draft Act on the consequences of the introduction of the common currency in some EU member states is under government consideration at the moment. The Act will regulate issues directly relating to the Polish law system resulting from the introduction of the new currency.