Klaviyo SMS Marketing: How to Set It Up and What's Worth Sending

Quick answer: Klaviyo SMS lets you text customers from the same Klaviyo account and the same profiles you already use for email. You turn it on under Settings > Text message, get your sending number verified, collect consent through sign-up forms and Shopify checkout, then add texts to your Welcome, Abandoned Cart and Abandoned Checkout flows. Every text costs money, so keep each one to 1 segment, send campaigns to engaged segments only, and save SMS for sale launches, last calls, product launches and restocks.

You're already on Klaviyo. Email works.

Then someone tells you to "add SMS".

Fair question: is it worth it, or is it just one more bill?

Here's our honest answer. SMS can make a Klaviyo brand good money. It can also lose money quietly while the dashboard says it's working. What decides it is what you send, who you send it to and how long the text is.

By Emiel Dingemans, Founder of Magicianly

Updated November 2026

What Is Klaviyo SMS?

Klaviyo SMS is the text messaging side of Klaviyo. You send texts from the same account as your email, with the same customer profiles, segments and flows.

That's the main reason we like it for brands that are already on Klaviyo. One profile per customer. One place to build flows. One place to see what each channel did. You don't need a second tool and a sync you have to keep an eye on.

Klaviyo groups SMS, MMS, RCS and WhatsApp under Mobile Messaging, and it's billed separately from your email plan. The free plan includes $5 of mobile messages a month. Enough to test. Not enough to run a program.

Is Klaviyo SMS Worth It?

Klaviyo SMS is worth it when your texts earn clearly more than they cost, and when the text does something email can't do as well. For most Shopify brands, that means a few flows and a handful of high-intent campaigns a month. Not a text for every email.

Email made all of us a bit lazy about cost. Sending one more email to 50,000 people costs next to nothing. Sending one more text to 50,000 people costs real money, every time. SMS has paid media economics, so we treat it like paid media.

Before you switch it on, ask yourself three questions:

• Do you have moments that are actually urgent? A sale with a real end date, a launch, a restock of something that sells out.
• Do your margins leave room? The lower your margin, the stricter you have to be about every send.
• Will someone check the cost of every send? If nobody puts the cost next to the revenue, SMS turns into revenue that isn't profit.

Three yeses? Set it up. If not, your email program probably still has bigger wins.

How Do You Set Up SMS in Klaviyo?

You turn on SMS under Settings > Text message, choose your countries, add your business details and policies, and wait until your sending number is verified before you send anything. Klaviyo's guide on how to set up SMS in Klaviyo shows every screen.

The short version:

1. 1Get your paperwork ready. For the US and Canada, you need your legal business name, business registration details, a published SMS privacy policy and mobile terms of service. Klaviyo can generate and host the mobile terms for you.
2. 2Turn on SMS. Go to Settings > Text message and click Set up texting for free. Only Owners, Admins and Managers can do this.
3. 3Pick your countries. The US and Canada get a free toll-free number. The UK and most European countries get a free branded sender ID, which shows your brand name as the sender.
4. 4Wait for verification. A US toll-free number takes about 2 to 5 business days to verify, and your website has to be live. Build your sign-up forms and flows in the meantime, but don't switch them on until the number shows as Active.
5. 5Check your UTM tracking. If you already use UTM tracking in Klaviyo, set the UTM medium to Message type under Settings > Other > UTM tracking. Otherwise SMS clicks may not be tracked properly.
6. 6Start sending soon after approval. Klaviyo recommends sending within a month of verification. A verified number that sits unused for weeks can lose its status with the carriers.

Then set quiet hours and Smart Sending in the same Text message settings. Klaviyo's standard quiet hours run from 8 p.m. to 11 a.m., and some US state rules override that.

A short code is a later decision. Klaviyo suggests considering one once you have more than 30,000 SMS subscribers or send campaigns to more than 30,000 people, because it sends much faster. It also comes with its own monthly fee and several weeks of carrier approval, so it's a speed decision first and a cost decision second.

How Do You Collect SMS Subscribers in Klaviyo?

You collect SMS subscribers with Klaviyo sign-up forms and with the SMS consent checkbox at Shopify checkout. You need a live sending number for a country before you can collect consent there.

Two places do most of the work:

• Your sign-up form. Ask for the email first, then the phone number on a second step. People who already gave you their email are the warmest SMS subscribers you'll get.
• Shopify checkout. In Klaviyo, go to Integrations > Shopify > Sync settings and turn on Sync your Shopify Text Message subscribers to Klaviyo. Then in Shopify, go to Settings > Checkout and switch on SMS under Marketing options. Klaviyo's guide to collecting SMS consent at Shopify checkout has the details.

Use a separate list for SMS subscribers, like Klaviyo recommends, so you can manage each channel on its own. And if you're moving from another SMS tool, import your existing subscribers instead of asking everyone to sign up again.

What Does a Klaviyo SMS Send Cost?

A Klaviyo SMS send costs your recipients times the number of segments times your rate per segment. Since July 13, 2026, Klaviyo bills mobile messages in dollars per message, with carrier fees included, as explained in Klaviyo's mobile messaging pricing FAQ.

Cost of a send = recipients x segments x your rate per segment

Your rate depends on the country, the channel and, in the US and Canada, the number type. On Klaviyo's list prices, a US text from a toll-free number costs about 1 to 1.5 cents per segment, and a UK text costs about 5 times as much. You'll find your own rates under Settings > Billing.

Here's what that does to one campaign. Say your rate is 1.15 cents per segment:

Same offer. Three very different bills.

The plan itself is prepaid, and unused spend doesn't roll over. We break down plan prices per month, short codes and MMS in how much SMS marketing costs.

Which Klaviyo SMS Campaigns Are Worth Sending?

The Klaviyo SMS campaigns worth sending are the ones where timing really matters: a sale launch, the day before a sale ends, the last hours of a sale, a product launch and a restock. Everything else usually works fine as an email.

What we usually skip: the extra sale reminders in between (Black Friday and Cyber Monday are the exception), newsletters, product highlights and anything that's just the email again in shorter form. Check it for your own brand, but start from there.

The test is simple. If email can do the job just as well, don't pay for the text. We go deeper on timing in our SMS marketing strategy, and there are ready-to-adapt texts in our SMS marketing examples.

Which Klaviyo Flows Should You Add SMS To?

Add SMS to your Welcome, Abandoned Cart and Abandoned Checkout flows first. Browse and site abandonment can be worth a text too, but test it, because the intent is lower.

In Klaviyo, you add a text to an existing email flow with a conditional split on "can receive text message marketing". The text goes on the YES path, your email stays on the NO path, and the paths rejoin after. Klaviyo recommends keeping the SMS welcome series separate from your email welcome series, because people often sign up for each at a different moment.

Start with one text per flow. Add a second only if it brings in clearly more than it costs. We walk through the email side of these flows in our Klaviyo welcome flow and abandoned cart flow guides.

Who Should You Send Klaviyo SMS Campaigns To?

Send SMS campaigns to your SMS subscribers segment, narrowed down by topic and volume, and always exclude people who bought in the last 3 days. Don't text the full list by default.

How we set up our segments in Klaviyo:

• Main segment: "SMS Subscribers". Everyone who can receive text message marketing.
• Narrower versions for most sends, like "SMS - 90 Days Engaged". Built on signals such as clicked an SMS or bought recently.
• Always exclude "Buyers Last 3 Days". Someone who just ordered doesn't need a sale text. You pay for it and you annoy them.

Start with the most engaged audience. Go broader only when the campaign deserves it, like a big sale launch. Every extra recipient is extra cost.

How Should You Write Klaviyo SMS Messages?

Write every Klaviyo SMS to fit in 1 segment, without emojis, as plain SMS. Klaviyo shows the segment count in the editor, so check it before every send.

Our default rules:

• 1 message, 1 segment. A second segment doubles the cost of the send. Don't pay twice for a slightly longer sentence.
• No emojis or special characters. One emoji can cut the limit from 160 characters to 70. A fire emoji isn't worth doubling the bill.
• No MMS. An image costs a lot more than a text, and it rarely earns that back. In Klaviyo, MMS only works from US and Canadian toll-free numbers and short codes, and Australian long codes, so UK brands can't use it anyway.
• Basic RCS where you can. Basic RCS costs about the same as SMS on Klaviyo in most countries, shows your brand name, and phones without RCS still get the SMS. We explain the setup in RCS business messaging.

The details on what pushes a text into a second segment are in our guide to the SMS character limit.

Is Klaviyo SMS Different in the UK?

Yes. UK texts on Klaviyo cost about 5 times as much as US texts on the list prices, the default sender is your brand name instead of a phone number, and MMS isn't available. So UK brands need to be even stricter.

A branded sender ID can't receive replies, so customers can't text STOP. Klaviyo adds an unsubscribe link instead, and that longer opt-out line can push a text into a second segment on its own. Same copy, different cost on each side of the Atlantic.

For UK sends, we get stricter on everything: smaller audiences, fewer campaigns, 1 segment always, and a harder look at whether the message needs to be a text at all.

How Do You Know If Your Klaviyo SMS Is Paying Off?

Put the cost of every send next to the revenue Klaviyo attributes to it. If you never see the cost, you can't judge the text.

And that red row assumes every dollar was caused by the text. Klaviyo can credit an order to a text that was only delivered, even if the customer never clicked and already saw the email that morning. We go into that in Klaviyo attribution. The full traffic light and the math behind it are in how much SMS marketing costs.

When a send looks weak, the fix is usually cheap: a smaller audience, a shorter text, or no text at all.

What Are the Most Common Klaviyo SMS Mistakes?

Most Klaviyo SMS mistakes come from treating SMS like email: same frequency, same audience, same copy length.

1. 1Texting the full list for every campaign. Segment SMS like you segment email.
2. 2Turning every email into a text. If email can do the job, skip the SMS.
3. 3Not checking the segment count. An emoji, a long link or a brand prefix can double the cost without anyone noticing.
4. 4Paying for MMS because the image looks nice. It has to earn its extra cost, and it usually doesn't.
5. 5Upgrading the plan for a lower rate. Unused spend expires. A lower rate on messages you never send is just a bigger bill.
6. 6Judging SMS on attributed revenue alone. Revenue isn't profit, and attributed revenue isn't always caused by the text.
7. 7Going live before the number is verified. Build everything first, then switch it on once the number is Active.

So Is Klaviyo SMS Marketing Worth It?

Klaviyo SMS marketing is worth it when every text earns its place. Set it up properly, text engaged segments, keep it to 1 segment, and use it for launches, restocks, sale moments and your highest-intent flows.

If you'd rather have us run SMS next to your email in one Klaviyo account, that's part of our Klaviyo management service. For the channel on its own, see our SMS marketing service.

Smaller audience. Shorter message. Higher intent.

Every text should earn the right to be sent.