Klaviyo SMS Marketing: What It Is and How to Set It Up
Almost every text message gets opened. That's the entire case for SMS marketing in one sentence — email open rates hover around 20%, SMS sits close to 98%. Klaviyo built SMS directly into the same platform as your email marketing, so the two channels share your customer data, your segments and your flows instead of running as two disconnected systems.
This isn't a replacement for email. It's a second channel that reaches the customers email increasingly can't: engagement on email drops sharply after the first 60 days of a subscriber relationship, and SMS gives you a way to stay in front of that audience without relying on an inbox they've stopped opening.
What Klaviyo SMS marketing actually is
Klaviyo SMS marketing lets you send text messages to customers who've opted in, using the same segmentation, flows and campaign tools you already use for email. Instead of building a separate SMS platform and syncing data between two systems, everything lives in one place: a customer's email engagement, purchase history and SMS activity all feed the same profile.
There are three message types worth knowing:
- Transactional SMS — order confirmations, shipping updates, delivery notifications. These aren't marketing messages and typically don't require the same opt-in as promotional texts, though Klaviyo still requires consent to send them.
- Promotional SMS — discount codes, product launches, sale announcements. This is what most people mean by "SMS marketing," and it requires explicit opt-in consent under US and UK regulations.
- Two-way SMS — customer service and support conversations, where the customer can reply and get a response rather than just receiving a broadcast.
Setting up Klaviyo SMS marketing: a step-by-step guide
- Register your sending number: In the US, this means 10DLC (10-digit long code) registration, a carrier-mandated process that verifies your business before you can send SMS at volume. This isn't optional and isn't instant. Budget for the registration lead time before you plan a launch date.
- Build your opt-in flow. SMS consent has to be collected separately from email consent. The most common approach is a checkbox on your existing email opt-in form, or a dedicated SMS-only popup offering a specific incentive (a discount code is the standard, though not the only option).
- Set up your core flows. Start with the same lifecycle moments you already have in email: welcome, abandoned cart, and post-purchase. Klaviyo lets you build these as SMS-only, email-only, or combined flows where the channel is decided by what you know about each subscriber.
- Decide your cadence for campaigns. SMS tolerates far less frequency than email before subscribers start opting out. Most brands send meaningfully fewer SMS campaigns per month than email campaigns — treat SMS sends as a higher-value, lower-frequency channel, not a copy-paste of your email calendar.
- Track the right things. Klaviyo will show you click rate and conversion rate by default, but neither tells you whether SMS is actually growing your business — they're efficiency metrics that decay naturally as your list matures, the same problem as email's Revenue Per Recipient. What actually matters: total SMS-attributed revenue, list growth rate, and unsubscribe rate as a signal you're sending too often or too generically.
Klaviyo SMS vs. dedicated SMS platforms
If you're comparing Klaviyo's native SMS against a dedicated platform (Attentive, Postscript, TextMagic and similar), the trade-off is integration versus specialisation. Klaviyo's SMS lives inside the same profile and flow-builder as your email, so segmentation and cross-channel logic ("if they didn't open the email, send SMS" style flows) work natively without a data sync between two tools.
Dedicated SMS platforms sometimes offer deeper SMS-specific features (richer MMS support, more granular compliance tooling in some cases), but you're managing two separate customer records and two separate opt-in systems as a result. For most brands already on Klaviyo for email, keeping SMS in the same platform outweighs the marginal feature gap.
A real client example
AS Beauty, one of the most iconic US skincare brands, folded SMS into a full CRM overhaul alongside email and qualitative research — including a dedicated SMS opt-in form to capture mobile subscribers for personalised text messaging. Their Senior Director of Retention credited the combined email and SMS work with driving the overall growth of the business.
FAQ
What is Klaviyo SMS marketing?
Klaviyo SMS marketing is text message marketing sent through the same platform as your Klaviyo email marketing, using shared customer profiles, segments and flows rather than a separate connected tool.
How do I set up SMS marketing in Klaviyo?
Register your sending number (10DLC in the US), build a dedicated SMS opt-in flow separate from email consent, set up your core flows (welcome, abandoned cart, post-purchase), and decide a campaign cadence that's lower-frequency than your email calendar.
What's the difference between Klaviyo SMS and a dedicated SMS platform like TextMagic?
Klaviyo SMS shares one customer profile and flow-builder with your email marketing, so cross-channel logic works natively. A dedicated SMS platform like TextMagic runs separately from your email tool, which can offer deeper SMS-specific features but means managing two disconnected customer records.
Do I need a separate agency for SMS, or does my email agency handle it too?
Most full-service Klaviyo agencies, including Magnet Monster, run SMS and email as one integrated strategy rather than two separate services, since they share the same platform, data and flows. See our Klaviyo email marketing agency page for the full scope.
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