Standard SMS can contain 160 characters. However, the characters must be part
of the so-called 7-bit default alphabet as specified by GSM 3.38 character set.
This alphabet contains all ASCII characters and some accented characters.
For example, u umlaut (ü) and e with grave (è) are in this set.
Using any character not in this set, will require the SMS to be treated as a Unicode
SMS and limit the length of the SMS to 70 characters due to the different character
encoding. See Article on
how to send Unicode messages:
Specific common characters that you should avoid using to ensure your message
is sent using the more efficient GSM character set are:
` should be '
‘ this apostrophe is formatted by MS Office.
Note the difference between ‘ and '
“ should be "
” should be "
~ should be -
¬ should be -
| should be avoided altogether, otherwise use an uppercase I
You can use the following tool to replace some of the unnecessary Unicode characters with equivalent GSM characters: http://mzone.wire2air.com/mserver/vas/UnicodeDetect.aspx
The GSM 03.38 7 bit character set
Dec
|
Hex
|
Char
|
Dec
|
Hex
|
Char
|
Dec
|
Hex
|
Char
|
Dec
|
Hex
|
Char
|
0
|
0
|
@
|
16
|
10
|
Δ
|
32
|
20
|
SP
|
48
|
30
|
0
|
1
|
1
|
£
|
17
|
11
|
_
|
33
|
21
|
!
|
49
|
31
|
1
|
2
|
2
|
$
|
18
|
12
|
Φ
|
34
|
22
|
"
|
50
|
32
|
2
|
3
|
3
|
¥
|
19
|
13
|
Γ
|
35
|
23
|
#
|
51
|
33
|
3
|
4
|
4
|
è
|
20
|
14
|
Λ
|
36
|
24
|
¤
|
52
|
34
|
4
|
5
|
5
|
é
|
21
|
15
|
Ω
|
37
|
25
|
%
|
53
|
35
|
5
|
6
|
6
|
ù
|
22
|
16
|
Π
|
38
|
26
|
&
|
54
|
36
|
6
|
7
|
7
|
ì
|
23
|
17
|
Ψ
|
39
|
27
|
'
|
55
|
37
|
7
|
8
|
8
|
ò
|
24
|
18
|
Σ
|
40
|
28
|
(
|
56
|
38
|
8
|
9
|
9
|
Ç
|
25
|
19
|
Θ
|
41
|
29
|
)
|
57
|
39
|
9
|
10
|
A
|
LF
|
26
|
1A
|
Ξ
|
42
|
2A
|
*
|
58
|
3A
|
:
|
11
|
B
|
|
27
|
1B
|
<ESC>
|
43
|
2B
|
+
|
59
|
3B
|
;
|
12
|
C
|
ø
|
28
|
1C
|
Æ
|
44
|
2C
|
,
|
60
|
3C
|
<
|
13
|
D
|
CR
|
29
|
1D
|
æ
|
45
|
2D
|
-
|
61
|
3D
|
=
|
14
|
E
|
Å
|
30
|
1E
|
ß
|
46
|
2E
|
.
|
62
|
3E
|
>
|
15
|
F
|
å
|
31
|
1F
|
É
|
47
|
2F
|
/
|
63
|
3F
|
?
|
Dec
|
Hex
|
Char
|
Dec
|
Hex
|
Char
|
Dec
|
Hex
|
Char
|
Dec
|
Hex
|
Char
|
64
|
40
|
¡
|
80
|
50
|
P
|
96
|
60
|
¿
|
112
|
70
|
p
|
65
|
41
|
A
|
81
|
51
|
Q
|
97
|
61
|
a
|
113
|
71
|
q
|
66
|
42
|
B
|
82
|
52
|
R
|
98
|
62
|
b
|
114
|
72
|
r
|
67
|
43
|
C
|
83
|
53
|
S
|
99
|
63
|
c
|
115
|
73
|
s
|
68
|
44
|
D
|
84
|
54
|
T
|
100
|
64
|
d
|
116
|
74
|
t
|
69
|
45
|
E
|
85
|
55
|
U
|
101
|
65
|
e
|
117
|
75
|
u
|
70
|
46
|
F
|
86
|
56
|
V
|
102
|
66
|
f
|
118
|
76
|
v
|
71
|
47
|
G
|
87
|
57
|
W
|
103
|
67
|
g
|
119
|
77
|
w
|
72
|
48
|
H
|
88
|
58
|
X
|
104
|
68
|
h
|
120
|
78
|
x
|
73
|
49
|
I
|
89
|
59
|
Y
|
105
|
69
|
i
|
121
|
79
|
y
|
74
|
4A
|
J
|
90
|
5A
|
Z
|
106
|
6A
|
j
|
122
|
7A
|
z
|
75
|
4B
|
K
|
91
|
5B
|
Ä
|
107
|
6B
|
k
|
123
|
7B
|
ä
|
76
|
4C
|
L
|
92
|
5C
|
Ö
|
108
|
6C
|
l
|
124
|
7C
|
ö
|
77
|
4D
|
M
|
93
|
5D
|
Ñ
|
109
|
6D
|
m
|
125
|
7D
|
ñ
|
78
|
4E
|
N
|
94
|
5E
|
Ü
|
110
|
6E
|
n
|
126
|
7E
|
ü
|
79
|
4F
|
O
|
95
|
5F
|
|
111
|
6F
|
o
|
127
|
7F
|
à
|
Some additional characters can be sent using the <ESC>
(0x1B) code in the above table plus an additional character; these extended characters are known as the Extended GSM character set and require 2 standard GSM characters per extended GSM character due to requiring the escape character prefix.
Note: Some of the characters will not be displayed correctly due to handset limitations
The Extended GSM character set
Dec
|
Hex
|
Char
|
27, 101
|
1B, 65
|
€
|
27, 10
|
1B, 0A
|
<FF>
|
27, 60
|
1B, 3C
|
[
|
27, 47
|
1B, 2F
|
\
|
27, 62
|
1B, 3E
|
]
|
27, 20
|
1B, 14
|
^
|
27, 40
|
1B, 28
|
{
|
27, 64
|
1B, 40
|
|
|
27, 41
|
1B, 29
|
}
|
27, 61
|
1B, 3D
|
~
|