Klaviyo SMS: Special Characters and the 70 Limit at BFCM

A Black Friday text written in French can lose more than half its length because of a single character. Klaviyo documents the rule and lists the characters involved. This article goes through it with the French cases: accented capitals, the c cedilla, the euro sign, quotation marks copied from a word processor. It complements our Klaviyo BFCM guide, which places the SMS channel within the overall preparation.

TL;DR. Klaviyo's page says an SMS segment holds up to 160 characters, or 70 if it contains an emoji or a special character. A single special character changes the encoding of the whole SMS, and a multi-segment message then holds 67 characters per segment, including the first. The page lists among special characters À, È, Ì, Ò, Ù, ç, ê, â, î, ô. It classes é and É among the non-special ones, and notes that the euro sign counts as 2 characters. In our view, checking every BFCM text with the calculator the page points to avoids discovering the switch on send day.

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The rule: 160 or 70

Klaviyo's page explains that special characters, which include emojis and certain types of text and symbols, shorten the character limit for a single SMS segment from 160 to 70 (Klaviyo, understanding special and non-special characters for SMS). The cause is encoding: before sending, each character is encoded into bits. The GSM-7 format (7-bit) is used for non-special characters: a segment holds up to 160 characters, with some symbols counting as 2. The UCS-2 format (16-bit) is used when the message contains special characters or emojis: a segment holds up to 70 characters. An emoji can count as more than one character: 😜 counts as 2 toward the 70-character limit.

The SMS campaign creation page repeats the limit: 160 characters per segment, or 70 with an emoji or certain special characters (Klaviyo, how to create and send an SMS campaign). Longer messages are split into multiple segments and cost more to send. The editor supports up to 1,600 characters in total.

Beyond the first segment

Using a special character or emoji changes the encoding for the whole SMS. A single segment holds up to 70 characters, but a message that needs multiple segments holds 67 characters per segment, including the first. Part of each segment is used to link the segments together: there is room for 134 characters across 2 segments or 201 across 3.

The page on Klaviyo's mobile messaging system specifies that a header reduces each segment's capacity to 153 characters, or 67 when the SMS contains an emoji or special character (Klaviyo, understanding Klaviyo's mobile messaging system).

French characters, according to the page

The page puts most non-special characters in the GSM-7 set: Latin letters, digits 0 to 9, some Greek letters, some symbols. What matters for French:

• Accented lowercase: à, è, ì, ò, ù are GSM-7 characters, but À, È, Ì, Ò, Ù are not, because capitalizing sometimes changes the classification. The page specifies that é and É are both GSM-7 characters.
• Cedilla: in the tables, only capital Ç appears among the non-special characters. Lowercase ç appears in the examples of special characters.
• Other accents: the examples of special characters notably cite á, â, ê, î, í, ô, ó and ú. In our view, û, absent from the tables and from the examples, should be tested in the calculator, since the page does not name it.
• Euro: the € sign is non-special, but it counts as 2 characters. The symbols marked with an asterisk in the page (\ [ ] { } | ~ ^) also count as 2.
• Punctuation: the period, comma, exclamation and question marks, colon, straight apostrophe ', straight double quotation mark ", parentheses and hyphen are among the non-special characters.

Emojis are special. For quotation marks, the page takes an example: the straight quotation mark " is non-special, and Klaviyo converts the quotation marks « , “ , ‟ , ❝ and 〝 to the straight quotation mark before sending. Klaviyo thus replaces some characters that look like GSM-7 characters, but not all of them.

Why "normal" text sometimes switches

The page flags a common case: text copied from a third-party source sometimes contains a special character that looks nearly identical to a non-special one. Its table pairs special versions of the letters a, d and e with their non-special versions. An accented letter can also be stored as a single character (é) or as a letter followed by a separate accent: the two look alike, but are not counted the same way.

The other special characters remain unchanged. The page advises retyping the message directly in Klaviyo, or using a text cleaner, then checking that every symbol is actually non-special.

Check before sending

The page says to paste the text into the message segment calculator it references, with Encoding set to Automatic and Smart Encoding set to No, then to read the Encoding line of the result: GSM-7 means the text contains only GSM-7 characters, UCS-2 means it contains at least one character outside GSM-7.

It warns that Klaviyo's automatic replacements can change the result: the estimated character and message counts in the SMS editor should be checked before sending, and counts can vary by recipient with personalized content.

The creation page asks you to add a link so Klaviyo can track clicks, and not to uncheck Automatically shorten links. According to the page on the mobile messaging system, shortened links and personalized content can change the final character count for each recipient. No page gives the length of a shortened link: we draw no calculation rule from it.

What one more segment changes in cost

For SMS, the page on the mobile messaging system says the rate applies to each segment and each recipient. Its formula for the total cost of a send: rate per segment, multiplied by the number of recipients, multiplied by the number of segments. An SMS that exceeds the single-segment limit is therefore billed per segment, even though it usually appears as one message to the recipient. Rates depend on the channel, the country and the number type, and are read in Settings > Billing: we reproduce no figures.

Campaigns and flows are billable, skipped messages (Smart Sending, no consent) are not, and failed deliveries (message blocked, device disconnected) are. In our view, a special character that takes a text from 153 to 67 characters per segment can add a segment for every recipient: the segment estimate in the editor should be read before scheduling.

MMS: what the pages say

An MMS allows up to 1,600 characters in a single message, and that limit does not change with emojis or special characters. The creation page specifies that the image or GIF must be under 600 KB, that availability depends on the recipient's country and the sending number, and that MMS costs more than SMS. It is billed as a single message. The creation page adds that MMS is not recommended during holiday seasons, without defining them: in our view, BFCM deserves to be treated as one, but that is Deliver's reading.

Sends delayed by throughput

Another point from the creation page, useful for a large send. SMS and MMS messages delayed by sending throughput can time out after around 4 hours and be skipped. Large campaigns may need to be split if the sending number is a long code, a toll-free number or a branded sender ID. This timeout is separate from the quiet-hours delay or skip setting, covered in our article on quiet hours and compliance.

What we would do for a BFCM text

These points are Deliver's advice.

1. Write the message in Klaviyo's editor, without pasting from another tool, with straight quotation marks and a simple hyphen (long dashes are absent from the page's tables).
2. Run each SMS through the calculator, then read the editor's estimates before scheduling.
3. If the message switches to UCS-2 because of an emoji or an accent, decide on purpose: rewrite to stay under 160, or accept the 70 limit (67 across several segments).
4. Apply the same check to SMS flows, not only to campaigns.

Our article on Klaviyo SMS in France presents the channel's general framework.

FAQ

How many characters in a Klaviyo SMS?

The page says 160 characters per segment, or 70 if the message contains an emoji or a special character.

Do accents take you down to 70 characters?

It depends on the letter, according to the page: é, É, à, è, ì, ò, ù are non-special, while À, È, Ì, Ò, Ù, ç, ê, â, î, ô are special.

Is the euro sign a special character?

No, but the page says it counts as 2 characters.

How many characters per segment on a longer message?

With a special character or an emoji, a multi-segment message holds 67 characters per segment, so 134 across 2 segments and 201 across 3.

How do you know if your SMS contains a special character?

With the message segment calculator cited by the page: GSM-7 means only GSM-7 characters, UCS-2 at least one character outside GSM-7.

Want an outside view on your BFCM texts? We run Q4 readiness audits, or you can talk directly with the Deliver team.