The standard SMS character limit is 160 characters per message. But that number only holds when every character in the message belongs to a small, specific alphabet. Add a single emoji, a curly apostrophe copied from a word processor, or a letter like "á", and the limit for the whole message drops to 70 characters.
If you send marketing texts, appointment reminders or two-factor codes, this matters: carriers and SMS providers bill per segment, so a message that quietly crosses a limit can cost two or three times what you expected. Before sending, paste the text into the Character Counter to check its length, then use the rules below to work out how many segments it will use.
Where the 160-character limit comes from
An SMS has a payload of 140 bytes (1,120 bits). The default SMS alphabet, defined in the GSM 03.38 standard, uses 7 bits per character, so 1,120 ÷ 7 = 160 characters.
That GSM-7 alphabet contains:
- the English letters A–Z and a–z and the digits 0–9
- common punctuation such as
. , ! ? ' " : ; ( ) - / & % # @ + = < > * - some accented letters used in Western European languages: é, è, ù, ì, ò, à, ä, ö, ü, ñ, ß, Ä, Ö, Ü, Ñ, Å, å, Ø, ø, Æ, æ, É
- currency symbols £, ¥ and $, and a handful of Greek capitals (Δ, Φ, Γ, Λ, Ω, Π, Ψ, Σ, Θ, Ξ)
Why one character can cut the limit to 70
If a message contains any character outside GSM-7, the phone or SMS gateway must switch the entire message to UCS-2 encoding, which uses 16 bits per character. 1,120 ÷ 16 = 70 characters.
Common characters that trigger this switch:
| Character | Why it sneaks in |
|---|---|
| ’ “ ” (curly quotes and apostrophes) | Word, Google Docs and phone keyboards "smart-quote" automatically |
| — (em dash) and … (ellipsis) | Auto-corrected from -- and ... |
| á, í, ó, ú, ê, õ, ç | Common in Spanish, Portuguese and French names |
| Emoji 😀 | Each emoji takes 2 of the 70 UCS-2 slots (it is a surrogate pair) |
| Non-Latin scripts (Arabic, Cyrillic, Chinese, Hindi…) | Not part of GSM-7 at all |
Some providers automatically replace smart quotes and dashes with plain equivalents to stay in GSM-7, but you cannot rely on that everywhere. The safest approach is to write SMS copy in a plain-text editor and replace curly quotes with straight ones.
Characters that count twice
GSM-7 also has an extension table of characters that need an escape code, so each one uses two of your 160 slots:
^ { } [ ] ~ \ | €
A promotional text that says "Save 20€ today" therefore uses 15 slots, not 14. Writing "EUR" or using a different currency format avoids the extra cost.
Long messages: the 153 and 67 rule
When a message is longer than a single SMS, it is split into multiple segments that the receiving phone stitches back together. Each segment carries a small header (the UDH, 6 bytes) that tells the phone the order of the parts. That header takes room away from your text:
| Encoding | Single SMS | Per segment when split |
|---|---|---|
| GSM-7 | 160 characters | 153 characters |
| UCS-2 (Unicode) | 70 characters | 67 characters |
So a 161-character GSM message is not 160 + 1: it becomes two segments of up to 153 characters each. Here is what that means in practice:
| Message length (GSM-7) | Segments billed |
|---|---|
| 1–160 | 1 |
| 161–306 | 2 |
| 307–459 | 3 |
| 460–612 | 4 |
| Message length (Unicode) | Segments billed |
|---|---|
| 1–70 | 1 |
| 71–134 | 2 |
| 135–201 | 3 |
| 202–268 | 4 |
A worked example
Consider this reminder:
Hi Ana, your appointment is tomorrow at 10:30. Reply YES to confirm or call us to reschedule. See you soon!
It is 107 characters, all GSM-7: 1 segment.
Now add a friendly emoji at the end: "See you soon! 😊". The message looks like 109 characters, but because of the emoji it is encoded as UCS-2, where the limit is 70 and segments hold 67. The emoji counts as two code units, so the message needs 110 units and becomes 2 segments. One small icon doubled the cost of every reminder.
How to keep SMS messages in one segment
- Draft in plain text. Avoid writing SMS copy in Word or Google Docs, which insert curly quotes and em dashes.
- Check the length before sending. Paste the message into the Character Counter and keep GSM-only messages at 160 characters or fewer.
- Skip emoji in transactional texts. Save them for messages where the extra segment is worth it.
- Shorten links. A full tracking URL can easily use 80+ characters. Use a short branded link instead.
- Watch personalisation fields. A template that fits with "Ana" may overflow with "Maximilian-Alexander". Test your longest realistic values.
- Remove double spaces and trailing spaces. They count too. The Whitespace Remover cleans them up in one step.
SMS vs. modern messaging
iMessage, WhatsApp, RCS and other chat apps do not use SMS segments, so these limits do not apply there. They matter for classic SMS — which is still what most businesses use for reminders, verification codes and alerts, because it reaches every phone without an app.
Frequently asked questions
How many characters can a single text message have?
160 characters if every character is in the GSM-7 alphabet, or 70 if the message contains any other character, such as an emoji or a curly quote.
Do spaces count in an SMS?
Yes. Spaces, line breaks and punctuation all count as characters.
How many characters does an emoji use?
An emoji forces the whole message into Unicode (70-character limit) and most emoji take two of those 70 slots.
Why was my 150-character message sent as two texts?
It almost certainly contained a non-GSM character — often a curly apostrophe (’) — which lowered the limit to 70 characters, splitting the message into 67-character segments.
Final takeaway
Think of the SMS limit as 160 or 70, with 153 or 67 per segment for longer messages. Plain characters keep you at 160; a single emoji or smart quote drops you to 70. Check every template in the Character Counter before it goes out to thousands of phones.