The design of the new 50 euro note is similar to the recent European series that preceded it, and it also has new and enhanced security features designed to make it easier for the public to recognize its legitimacy.
To ensure that we have been handed the new legal tender and not any counterfeit notes, here's a few security features that we can check ourselves;
1) The new notes incorporate a watermark with the portrait of Europe that is visible in light.
2) It also has emerald green numbers with the digits "50", located in the lower left corner of the front.
3) It contains a "portrait window", located at the top right of the hologram.
In the light, this window becomes transparent and shows a portrait of Europe on both sides of the note. When tilting it, the window has multicoloured lines around the number that represents the value of the note, while on the reverse, there are multicoloured numbers that actually indicate the value of the note.
Sources from the European Central Bank said that once it is announced that the first series banknotes are no longer legal tender, they will retain their value for the purpose of exchanging them for the new notes at the central banks until all older ones have been phased out.