However that is not yet a real 'security' mark.
Is there a way to find out if a banknote is real, by looking at the serial number?
No and yes...
At least we can find out if a serial number is real or fake.
A fake serial number means at least that the banknote might be false (or a misprinted number ?)
Let's go back to the list of serial codes I gave before :
Z is for Belgium = 9
Y is for Greece = 1
X is for Germany = 2
W is reserved for Denmark (but not using Euro yet) = 3
V is for Spain = 4
U is for France = 5
T is for Ireland = 6
S is for Italy = 7
R is for Luxemburg (Luxemburg is producing its banknotes abroad so far) = 8
Q is not in use = 9
P is for the Netherlands = 1
O is not in use = 2
N is for Austria = 3
M is for Portugal = 4
L is for Finland = 5
K is reserved for Sweden (but not using Euro yet) = 6
J is reserved for UK (but not using Euro yet) = 7
I is not in use = 8
H is for Slovenia = 9
G is for Cyprus = 1
F is for Malta = 2
E is for Slovak Republic = 3
D is for Estonia = 4
1 = Y; P and G
2 = X; (O); and F
3 = W; N and E
4 = V; M and D
5 = U; L
6 = T; K
7 = S; J
8 = R; (I)
9 = Z; (Q) and H
Let's take some notes :
Y02669777425 => 0+2+6+6+9+7+7+7+4+2+5 = 55 => 5 + 5 = 10 => 1 + 0 = 1
X31808174321 => 3+1+8+0+8+1+7+4+3+2+1 = 38 => 3 + 8 = 11 => 1 + 1 = 2
V26229374041 => 2+6+2+2+9+3+7+4+0+4+1 = 40 => 4 + 0 = 4
U55586646086 => 5+5+5+8+6+6+4+6+0+8+6 = 59 => 5 + 9 = 14 => 1 +4 = 5
T15550427427 => 1+5+5+5+0+4+2+7+4+2+7 = 42 => 4 +2 = 6
As you see, all banknotes above correspond to their controle numbers.
A logic consequence of this system is, that succeeding banknotes should always have a difference of 9 in the serial number :
See for these brand new notes, in order of printing :
as you see, each serial number has a difference of 9 with the previous number. The check sum always remains the same (2 in this case).