The five hundred euro note is protected by:
Colour changing ink used on the numeral located on the back of the note, that appears to change colour from purple to brown, when the note is tilted.

A transparent number printed in the top corner of the note, on both sides, appear to combine perfectly to form the value numeral when held against the light.

A glossy stripe, situated at the back of the note, showing the value numeral and the euro symbol.

A hologram, used on the note which appears to see the hologram image change between the value and a window or doorway, but in the background, it appears to be rainbow-coloured concentric circles of micro-letters moving from the centre to the edges of the patch.

A EURion constellation; the EURion constellation is a pattern of symbols found on a number of banknote designs worldwide since about 1996.
It is added to help software detect the presence of a banknote in a digital image.

Watermarks, which appear when held up to the light.

Raised printing in the main image, the lettering and the value numerals on the front of the banknotes will be raised.

Ultraviolet ink; the paper itself does not glow, fibres embedded in the paper do appear, and be coloured red, blue and green, the EU flag is green and has orange stars, the ECB President's, currently Mario Draghi's, signature turns green, the large stars and small circles on the front glow and the European map, a bridge and the value numeral on the back appear in yellow.

Microprinting, on various areas of the banknotes there is microprinting, for example, inside the "ΕΥΡΩ" (EURO in Greek characters) on the front.
The micro-text is sharp, not blurred.

A security thread, embedded in the banknote paper.
The thread will appear as a dark stripe when held up to the light.
The word "EURO" and the value is embedded in tiny letters on the thread.

Perforations in the hologram which will form the euro symbol.
There are also small numbers showing the value.

A matted surface; the note paper is made out of pure cotton, which feels crisp and firm, but not limp or waxy.

Barcodes,
A serial number.
The five hundred euro note is protected by:
Colour changing ink used on the numeral located on the back of the note, that appears to change colour from purple to brown, when the note is tilted.
A transparent number printed in the top corner of the note, on both sides, appear to combine perfectly to form the value numeral when held against the light.
A glossy stripe, situated at the back of the note, showing the value numeral and the euro symbol.
A hologram, used on the note which appears to see the hologram image change between the value and a window or doorway, but in the background, it appears to be rainbow-coloured concentric circles of micro-letters moving from the centre to the edges of the patch.
A EURion constellation; the EURion constellation is a pattern of symbols found on a number of banknote designs worldwide since about 1996. It is added to help software detect the presence of a banknote in a digital image.
Watermarks, which appear when held up to the light.
Raised printing in the main image, the lettering and the value numerals on the front of the banknotes will be raised.
Ultraviolet ink; the paper itself does not glow, fibres embedded in the paper do appear, and be coloured red, blue and green, the EU flag is green and has orange stars, the ECB President's, currently Mario Draghi's, signature turns green, the large stars and small circles on the front glow and the European map, a bridge and the value numeral on the back appear in yellow.
Microprinting, on various areas of the banknotes there is microprinting, for example, inside the "ΕΥΡΩ" (EURO in Greek characters) on the front. The micro-text is sharp, not blurred.
A security thread, embedded in the banknote paper. The thread will appear as a dark stripe when held up to the light. The word "EURO" and the value is embedded in tiny letters on the thread.
Perforations in the hologram which will form the euro symbol. There are also small numbers showing the value.
A matted surface; the note paper is made out of pure cotton, which feels crisp and firm, but not limp or waxy.
Barcodes,
A serial number.
500 euro note