SMS Character Encoding

The way characters are encoded in the message body has a direct impact on the number of SMS messages sent.

The character set used determines the type of encoding that will be applied when sending an SMS.

Supported Character Set

A single SMS message can hold up to 160 characters if all the characters belong to the GSM 7-bit character set:

	x0	x1	x2	x3	x4	x5	x6	x7	x8	x9	xA	xB	xC	xD	xE	xF
0x	@	£	$	¥	è	é	ù	ì	ò	Ç	LF	Ø	ø	CR	Å	å
1x	Δ	_	Φ	Γ	Λ	Ω	Π	Ψ	Σ	Θ	Ξ	ESC	Æ	æ	ß	É
2x	SP	!	“	#	¤	%	&	‘	(	)	*	+	,	-	.	/
3x	0	1	2	3	4	5	6	7	8	9	:	;	<	=	>	?
4x	¡	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O
5x	P	Q	R	S	T	U	V	W	X	Y	Z	Ä	Ö	Ñ	Ü	§
6x	¿	a	b	c	d	e	f	g	h	i	j	k	l	m	n	o
7x	p	q	r	s	t	u	v	w	x	y	z	ä	ö	ñ	ü	à
1B 0x											FF
1B 1x				ˆ
1B 2x								{	}					\
1B 3x												[	˜	]
1B 6x						€

LF is the Line Feed character. For JSON format, provide it as \n.

SP is the Space character.

Extended Characters

Some special characters take up more space and are counted as two characters in an SMS message:
, ˆ € { } [ ] ˜ \

Unicode Characters

If the message includes characters from other languages, 16-bit Unicode (UCS-2) encoding is used. Each character will then consume 2 bytes, reducing the maximum characters per SMS to 70.

Message Length and Segmentation

The message body can contain up to 800 characters. However, due to encoding constraints, messages exceeding the character limits are split into multiple SMS segments and reassembled by the recipient's device.

Using 7-bit Encoding:

Message Length	Number of SMS Parts
1-160	1
161-306	2
307-459	3
460-612	4
613-765	5

Using Unicode Encoding:

Message Length	Number of SMS Parts
1-70	1
71-134	2
135-201	3
202-268	4
269-335	5

Note: Messages exceeding 5 parts will result in an error.