SMS Billing

This section provides detailed information regarding how SMS message costs are calculated. The cost of sending a message is strictly tied to the message length and the type of characters used.

Important: The rules below apply to all SMS messages sent via the platform, including those created manually in the Campaign Builder and those sent automatically via the SMS API.

SMS Calculation Rules

The length of a single SMS depends on the encoding standard, which the system selects automatically based on the message content. While the limits below are global standards, minor differences may occur in rare cases depending on the recipient's mobile carrier.

Standard Message (GSM-7 encoding)

Your message is encoded in GSM-7 standard if it contains only characters from the basic Latin alphabet (A-Z, 0-9) and basic punctuation marks.

• Limit for 1 SMS: 160 characters.

• Concatenated messages (longer than 160 characters): If you exceed the limit, the system must combine the messages into one. This consumes a few technical characters (UDH header). In this case, each message part holds 153 characters.

GSM-7 Character Table (Counted as 1 character)

The following characters are safe and occupy only 1 character within the message limit.

Char	Description	Char	Description	Char	Description
@	At sign	SP	Space	!	Exclamation mark
"	Quotation mark	#	Hash	%	Percent
&	Ampersand	'	Apostrophe	(	Opening parenthesis
)	Closing parenthesis	*	Asterisk	+	Plus
,	Comma	-	Hyphen	.	Dot
/	Slash	:	Colon	;	Semicolon
<	Less than	=	Equals	>	Greater than
?	Question mark	_	Underscore	¡	Inverted exclamation
£	Pound	$	Dollar	¥	Yen
§	Section sign	¿	Inverted question	¤	Currency sign
A-Z	Uppercase letters	a-z	Lowercase letters	0-9	Digits

Greek Uppercase Letters and Special Symbols (GSM-7): The following characters also belong to the basic GSM-7 set and are counted as 1 character, although their display depends on the recipient's device:

Δ Φ Γ Λ Ω Π Ψ Σ Θ Ξ Ä ä Ö ö Ñ ñ Ü ü à ò ù å Å è é É ì ç Ø ø Æ æ ß

Extended Character Table (GSM-7 Extension - Counted as 2 characters)

Note! The following characters, although they do not switch to Unicode encoding, occupy 2 bytes. This means each of them takes up 2 characters from the available limit (160).

Char	Name	Character count in SMS
^	Caret	2
{	Opening brace	2
}	Closing brace	2
\	Backslash	2
[	Opening bracket	2
~	Tilde	2
]	Closing bracket	2
|	Pipe (Vertical bar)	2
€	Euro symbol	2

SMS Calculation for GSM-7 Characters

Number of Characters	Number of SMS Messages
1 - 160	1
161 - 306	2
307 - 459	3
460 - 612	4
613 - 765	5
766 - 918	6
919 - 1071	7
1072 - 1224	8
1225 - 1377	9

Message with special characters (Unicode encoding)

Using even one character not found in the tables above (e.g., a specific diacritic mark or an emoji) automatically switches the entire message encoding to Unicode (UCS-2). This drastically reduces the character limit.

Examples of characters triggering Unicode:

• Polish characters: ą, ć, ę, ł, ń, ó, ś, ź, ż.

• Central/Eastern European Languages: Czech/Slovak (č, š, ž, ř), Hungarian "long" umlauts (ő, ű), Romanian (ș, ț).

• Western European Traps: French circumflex (â, ê, î), Spanish/Portuguese accents (á, í, ó, ú, ã). (Note: characters like é, è, ñ, ç are safe and do not switch encoding).

• Other Scripts: Cyrillic (e.g., Д, ж), Hebrew (e.g., ש, ל), Arabic (e.g., م, ل).

• Emoji: e.g., 🙂, 🔥, ❤️, 👍.

Unicode Limits:

• Character limit: 70 per single SMS.

• Concatenated messages (longer than 70 characters): Each part of the concatenated message holds 67 characters.

SMS Calculation for Unicode Characters

Number of Characters	Number of SMS Messages
1 - 70	1
71 - 134	2
135 - 201	3
202 - 268	4
269 - 335	5
336 - 402	6
403 - 469	7
470 - 536	8
537 - 603	9

Important Information on Personalization

If you use dynamic parameters (e.g., {{name}} in the builder or variables in the API), the final SMS length may differ for each recipient.

• Example: Suppose your message template (Unicode) is 65 characters long.

  • For the name "Anna" (4 characters) – the message is 69 characters total. It fits within the 70 limit. -> Cost: 1 SMS.

  • For the name "Katherine" (9 characters) – the message is 74 characters total. It exceeds the 70 limit. -> Cost: 2 SMS.

Best Practice: When planning your campaign budget, always include a character margin for the longest data in your database (e.g., long surnames or city names) to avoid unexpected doubling of shipping costs.

Always check the character counter in the campaign editor as well. Our system informs you in real-time how many parts your SMS will consist of.