© European Union - European Parliament
The continuous monitoring of the circulation by the National Bank and its colleagues ensures that the banknotes retain all their security features; badly worn notes can be handed in to the National Bank, which will exchange them subject to certain conditions.
This monitoring also ensures the early interception of forgeries. Well protected, the euro is an international currency; so we could say that it is "the victim of its own success", a bit like the dollar... Counterfeiting is an age-old phenomenon, and there is no such thing as a banknote that cannot be forged. The best defence is to be very familiar with the security features, and to check several of them if possible.