In which year did euro notes and coins begin to be circulated?

Banknotes of the euro, the currency of the euro area and institutions, have been in circulation since the first series (also called ES1) was issued in 2002. They are issued by the national central banks of the Eurosystem or the European Central Bank. In 1999 the euro was introduced virtually, and in 2002 notes and coins began to circulate. The euro rapidly took over from the former national currencies and slowly expanded around the European Union.

Denominations of the notes range from €5 to €500 and, unlike euro coins, the design is identical across the whole of the Eurozone, although they are issued and printed in various member states. The euro banknotes are pure cotton fibre, which improves their durability as well as giving the banknotes a distinctive feel. They measure from 120 by 62 millimetres (4.7 in × 2.4 in) to 160 by 82 millimetres (6.3 in × 3.2 in) and have a variety of colour schemes.

The euro notes contain many complex security features such as watermarks, invisible ink characteristics, holograms, optically variable inks and microprinting that document their authenticity. While euro coins have a national side indicating the country of issue (although not necessarily of minting), euro notes lack this. Instead, this information is shown by the first character of each note's serial number.