SMS Length for Marketing: How Long Your Texts Should Be
A single SMS holds 160 characters, but a marketing text should usually be shorter: aim for roughly 100 to 150 characters, state one idea, and leave a buffer so a long name, a link or one stray emoji does not push the message into a second segment. The right length is the one that identifies you, gives a reason for the text and asks for one reply, nothing more.
This guide covers the technical limits, the way encoding quietly changes them, a practical length target for lead follow-up, how links and link tracking eat into your count, and the U.S. consent rules that matter more than any character count.
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TL;DR
One SMS is 160 characters in standard GSM-7 encoding. Add a single character outside that set and the limit drops to 70.
Longer messages are split into segments of 153 characters (GSM-7) or 67 (Unicode), so two segments hold 306 characters, not 320.
For marketing and lead follow-up, write 100 to 150 characters: who you are, why you are texting, one next step.
Count the message after personalization and link insertion, not as a template.
Length never replaces consent. In the U.S., advertising texts generally need prior express written consent.
The numbers behind SMS length
SMS was designed around a payload of 140 bytes. That is where 160 comes from: at 7 bits per character, 140 bytes fit 160 characters. The limit you see in your texting tool is a byte budget, a point the AWS messaging documentation makes when it notes that the 160-character-per-message limit forces concise writing.
Here is the reference table most senders keep nearby. The figures match what SMS segmentation guides list for the two common encodings.
Encoding | Single message | Each part of a multi-part message | Two parts hold | Three parts hold |
|---|---|---|---|---|
GSM-7 (basic Latin text) | 160 | 153 | 306 | 459 |
Unicode / UCS-2 | 70 | 67 | 134 | 201 |
The gap between 160 and 153 exists because every part of a split message needs a small header that tells the phone how to reassemble it. That header uses up capacity. So the moment you cross 160, you do not get 160 plus a few more. You get two segments of 153, and you are billed for two messages by most carriers and platforms.
Why a message can jump segments without looking longer
The encoding is chosen for the whole message. If everything is in the basic GSM-7 character set, you get 160. If one character falls outside it, the entire message switches to Unicode and the ceiling falls to 70. Common triggers include:
Emojis
Curly “smart” quotes and apostrophes pasted from a word processor
Long dashes and ellipsis characters
Accented letters that are not in the basic set
You can see the effect in a real follow-up. This message uses a straight apostrophe and is 144 characters, so it travels as two GSM-7 segments at most:
Hi Sam, it’s Lee at Harbor Insurance. Your quote is ready. Want me to walk you through it? Reply YES and I’ll call today. Reply STOP to opt out.
Replace one apostrophe with a curly one copied from a document and the identical sentence becomes Unicode. At 144 characters it now needs three segments of 67. Same words, one extra segment, higher cost, and a message that may arrive as three fragments on some devices. A simple fix: paste copy into a plain-text editor, or turn off smart punctuation in your templates.
How long should a marketing text be?
The 160 ceiling is a limit, not a target. Ranking guides vary on the sweet spot, with some recommending 100 to 130 characters and others 75 to 115. The honest reading is that there is no verified magic number. What the sources agree on is direction: shorter is easier to read, cheaper to send and less likely to trigger a second segment.
Plain-language guidance from Digital.gov points the same way: express one idea per sentence, because long sentences often signal that you are unsure what you want to say. A text message is the extreme case of that advice.
For service businesses, we use this working range:
Message type | Target length | Why |
|---|---|---|
First reply to a new lead | 100 to 150 characters | Identify yourself, acknowledge the request, offer one next step |
Appointment confirmation | 80 to 130 characters | Date, time, reply option |
Reminder | 60 to 110 characters | Nothing to persuade, only to prompt |
Nurture or check-in | 100 to 150 characters | One question, one reason |
Offer or announcement | Up to two segments, deliberately | Only when the extra detail changes the decision |
Treat 150 as your soft ceiling. That leaves a few characters of room under 160 for the surprises described next.
Leave a buffer for personalization
The most common cause of accidental extra segments is dynamic data. A template written with a short first name in mind will meet someone named Alexandria, a business name with 30 characters, or an address that runs long. If your template lands at exactly 158 characters with a placeholder, real data will push some recipients over.
The rule: measure the longest realistic version of each field, not the typical one. If first names run up to 12 characters, count 12 for the placeholder.
Worked example: a contractor’s first reply
Here is a first reply to someone who just requested a roofing estimate (the name filled in):
Hi Maria, it’s Dana at Ridge Roofing. Thanks for requesting an estimate. Can we visit Thursday at 10 or 2? Reply 1 or 2. Reply STOP to opt out.
That is 143 characters. It names the sender, acknowledges the request, offers a choice of two times, tells the lead how to answer, and includes an opt-out line. One segment.
Now the version many teams write first:
Hi Maria, this is Dana with Ridge Roofing. Thanks for asking about a roof estimate! We can visit Thursday at 10 AM or 2 PM, whichever works. Reply 1 or 2 and I’ll confirm. Reply STOP to opt out.
That is 194 characters, so it becomes two segments of 153 each. It is friendly and fine, but it says the same thing at higher cost, and the reader has more to scan on a lock screen. Cutting is almost always an improvement.
One more case, with an emoji:
Hi Maria 👋 it’s Dana at Ridge Roofing. Can we visit Thursday at 10 or 2? Reply 1 or 2. Reply STOP to opt out.
It is only about 110 characters, yet the emoji forces Unicode, so it needs two 67-character segments. A cute wave doubled the sending cost of a message that would otherwise have been one segment.
What to put in a short text
When space is tight, order matters. For lead response, the structure that holds up is:
Who you are. Your first name and business name, so the recipient knows the number.
Why you are texting. Reference the action they took: a form, a quote request, a call.
One next step. A single question or reply option, such as two time slots.
Opt-out language where your program requires it, usually on the first message and periodically after.
What to leave out: your entire value proposition, multiple questions, a list of services, and a second call to action. If a lead needs more, they will reply, and the next message can carry it. Our guide with paste-ready SMS lead follow-up templates shows this structure across several service trades, and the SMS call-to-action examples cover how to word that single next step.
If you are building the broader automation behind these messages, a step-by-step marketing automation checklist is a useful companion for mapping triggers, timing and handoffs before you write a single template.
Links, link tracking and your character count
A link is the single biggest consumer of space in a marketing text. A full URL with tracking parameters can run 80 to 150 characters on its own, which is the whole message. That is why most SMS programs use short links.
How SMS link tracking generally works:
Your platform replaces the long URL with a short one on a domain it controls.
The recipient taps it and is redirected to the real destination.
The platform logs the click and ties it to the contact and the campaign.
That gives you click data without putting UTM parameters in the visible text. A few practical points:
Count the shortened link, not the original. Check what your tool actually inserts, because the short domain and its path length vary by platform.
Prefer one link per message. Two links double the space cost and dilute the action.
Consider whether you need a link at all. For lead follow-up, a reply-based action (“Reply 1 or 2”) keeps the text short and the conversation moving without a click. Booking links work when the lead has already shown strong intent.
Keep the link in a tidy position. Put it after the sentence that explains why they should tap it, so the text reads naturally on a preview screen.
Use a link you control or trust. Messages with unfamiliar or heavily reused shortener domains can look suspicious to recipients, and carriers filter on content signals, so test before sending at volume.
If you collect leads from your website, our walkthrough on click-to-SMS on a website shows how to start the conversation from the lead’s own phone, which avoids the link-length problem altogether.
Long texts versus short texts: when two segments make sense
Short is the default, not a law. Two segments can be the right call when:
You are sending a confirmation that includes an address, a time and a short instruction, such as where to park or what to bring.
A reminder must include a required notice.
The extra detail removes a back-and-forth that would otherwise take two or three messages.
It rarely makes sense to go to three or more segments in marketing. Past two, the message reads as a block of text, the cost multiplies, and delivery order across segments is less predictable. If you need that much room, send two separate messages with a short delay, each with its own single idea, or move the detail to a page and send one clean link.
Budget matters too. A campaign to 5,000 contacts at two segments each is 10,000 billable segments, double the one-segment version. Check your own platform’s pricing before assuming a length is free.
Our perspective: speed and clarity beat length
We build lead-response software for service professionals, so we see what happens right after a lead comes in. The pattern is consistent: the text that gets a reply is not the most persuasive one, it is the one that arrives quickly and asks something easy to answer.
Three things we hold to:
Write in the business’s own voice, then trim. A reply that sounds like you reads as shorter than it is. Our conversational AI learns how each business writes, so a first reply to a new lead sounds like a person at that company, not a template. Voice is also what lets you cut words safely: you do not need a paragraph of warm-up when the tone already carries it.
One message, one job. For a real estate agent it is a showing time. For a contractor it is an estimate window. For an insurance agent it is a call about a quote. For a financial advisor it is a first conversation. A text that tries to do two jobs usually does neither.
Measure after personalization. Most length problems are not in the template. They show up when real names, addresses and links fill the fields. Whatever tool you use, preview the longest realistic version of every message before it goes live.
Length is one lever. Timing is a bigger one, and our piece on when texting beats calling and why to reply within 60 minutes goes into that.
— Jamaal
Consent comes before length
A perfectly sized text sent without permission is still a problem. For U.S. marketing, the FCC states that robotexts containing advertising or telemarketing generally require prior express written consent under the TCPA, as laid out in its declaratory ruling materials. Industry guidance from CTIA adds that senders should give a clear call to action, obtain opt-in for the specific campaign, and honor opt-outs.
That has direct consequences for message length:
Your first message in a program often has to carry identity and opt-out language. Budget roughly 20 to 30 characters for “Reply STOP to opt out” and the sender name before you write a word of content.
Opt-out words must be honored whatever the message length. Build the confirmation reply as its own short message.
If you reply to someone who texted you first, the context differs from a cold campaign, but rules still apply. When unsure, ask a TCPA attorney, since this article is not legal advice.
For details, see our guides to TCPA compliance for SMS and double opt-in for SMS. If you work in healthcare or therapy, read what U.S. practices must get right for HIPAA text reminders before putting any health detail in a text, and keep messages even leaner. Insurance teams will find consent-aware examples in our insurance text templates.
A pre-send checklist for message length
Run every template through these seven checks:
Paste into a plain-text editor to strip smart quotes and hidden formatting.
Check for emojis and accented characters, and decide whether each is worth the Unicode switch.
Fill the placeholders with the longest realistic name, business and address.
Insert the shortened link your platform will actually generate and recount.
Confirm the total is at or under about 150 characters, or deliberately two segments.
Confirm the message has one sender, one reason and one action.
Confirm the opt-out language and consent basis are in place.
If you want to go further, the same discipline applies to multi-step conversations. Our guide to qualifying leads with a three-message SMS sequence shows how to spread questions across short messages rather than cramming them into one, and SMS personalization recipes cover how to add fields without breaking your length budget.
Let the software handle the first reply
Writing a tight first message is easy once. Doing it for every new lead, at any hour, in your own voice, is where most small teams fall behind. Astreaux is an AI-driven platform for service professionals that replies to new leads instantly through conversational AI, trains on your business’s voice, books appointments, runs bulk SMS campaigns and connects to your CRM and ad platforms through integrations with over 7,000 apps. It is built for real estate agents, contractors, insurance agents, financial advisors and therapists who want fast, personalized follow-up without manual texting.
FAQ
What is the maximum length of one SMS?
One SMS is 160 characters in standard GSM-7 encoding, or 70 characters if the message contains any character outside that set, such as an emoji. Longer messages are split into segments of 153 or 67 characters respectively. Platforms usually bill per segment.
How long should a text be for marketing or lead follow-up?
Aim for about 100 to 150 characters. That is enough to name yourself, reference the lead’s request and offer one next step, while leaving room under 160 for longer names and links. There is no single proven ideal, so test your own audience.
Do emojis hurt SMS marketing?
They change the math. One emoji switches the whole message to Unicode and cuts the limit to 70 characters, which can double your segments and cost. Use one only if it clearly earns its place, and always recount afterward.
How does SMS link tracking work?
Your platform swaps the original URL for a short link on its own domain. When someone taps it, they are redirected to the real page and the click is recorded against that contact and campaign. Count the short link in your character total, and use one link per message.
Does a short message exempt me from consent rules?
No. Under the TCPA, advertising or telemarketing texts to U.S. numbers generally need prior express written consent, regardless of length. Build opt-in records and honor opt-outs from the first message, and consult an attorney about your specific program.
