[10] Estimates suggest that the average life of a twenty euro banknote is about two years before it is replaced due to wear.

The twenty euro note contains several complex security features such as watermarks, invisible ink, holograms and microprinting that document its authenticity.

Euro cash was not introduced until 1 January 2002, when it replaced the national banknotes and coins of the countries in eurozone 12, such as the Belgian franc and the Greek drachma.

[19] The changeover period during which the former currencies' notes and coins were exchanged for those of the euro lasted about two months, going from 1 January 2002 until 28 February 2002.

[13] The earliest date was in Germany, where the mark officially ceased to be legal tender on 31 December 2001, though the exchange period lasted for two months more.

Even after the old currencies ceased to be legal tender, they continued to be accepted by national central banks for periods ranging from ten years to forever.

[24] While broadly similar to the previous notes, minor design changes include an updated map and a hologram of Europa.

It would be the first time in which the Bulgarian Cyrillic alphabet would be used on the banknotes as a result of Bulgaria joining the European Union in 2007.

[30] Although Robert Kalina's original designs were intended to show real monuments, for political reasons the bridge and art are merely hypothetical examples of the architectural era.

Besides the date of the introduction of the first set to January 2002, the publication of figures is more significant through the maximum number of banknotes raised each year.

In practice, only the national central banks of the zone physically issue and withdraw euro banknotes.