A1Z26 is a simple code that only replaces the alphabeth with their corresponding number.

Like this...

A = 1
B = 2
C = 3
D = 4
E = 5
F = 6
G = 7
H = 8
I = 9
J = 10
K = 11
L = 12
M = 13
N = 14
O = 15
P = 16
Q = 17
R = 18
S = 19
T = 20
U = 21
V = 22
W = 23
X = 24
Y = 25
Z = 26

8 1 22 5  6 21 14  4 5 3 15 4 9 14 7!