The Ultimate Guide to Using Klaviyo SMS in Your Multichannel Marketing Mix

So you have been literally around the block with marketing channels, trying to find that perfect balance for your brand/business. Email, social ads, push notifications, retargeting… The list feels endless, right? At this point, adding SMS to the mix might feel like opening Pandora’s box.

We get it. You might be wondering:

• Does SMS actually get noticed, or does it just get ignored?
  
• Will my customers think it’s spammy or intrusive?
  
• How do I even start using SMS effectively without annoying my list?
  
• And most importantly, does it play well with everything else I’m doing?
  

These are the exact questions we, at Mavlers, get from clients every day.

Here’s the honest answer: SMS marketing, when done thoughtfully, is not just another channel; it’s the one that connects your brand and customers on a personal level, faster and a lot more directly.

And when you use a platform like Klaviyo, built specifically to integrate SMS with email and ads, you get a powerful tool that cuts beyond noise and delivers personal, timely, high-impact messages your customers actually want to get.

Think of SMS as your brand’s VIP hotline, not a megaphone. It’s where you can reach your customers right when it matters, in a way that’s intimate and attention-grabbing.

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Why SMS marketing still commands attention and how it seamlessly fits into the bigger marketing picture

Honestly, today’s marketing space can look cluttered. Your customers are bombarded by emails, ads, social posts, and more. 

So, it’s natural to ask: Where does SMS fit in all this? Is it just another channel to add on, or is there something uniquely valuable about texting?

The answer lies in what SMS brings to the table, alongside your existing marketing efforts.

First, here’s a powerful fact: 98% of SMS messages get opened. That’s nearly universal attention. For context, emails average around 20% open rates, and social ads rely on eyeballs that are constantly flicking past. SMS gets your message seen almost every single time.

But it’s not about replacing email or other channels. It’s about meeting your customers where they are and giving them an extra nudge when timing matters most. Because here’s something amazing: 90% of SMS messages are read within 3 minutes. Imagine the potential when you combine that speed with the precision of marketing automation.

Automated SMS flows, like welcome messages, abandoned cart reminders, and post-purchase updates, deliver an average 29x return on investment. That’s not magic, it’s the conflation of strategy and relevance meeting in the perfect moment.

SMS works best as part of a multichannel approach, a way to complement your emails, social media, and ads. 

It’s that timely personal text that has the potential to prompt action when an email sits unopened or an ad might get ignored.

So, why does SMS still command such attention? 

Well, because it’s immediate, personal, and direct. 

But, and this is crucial, it only works if you use it thoughtfully, respecting your customers’ preferences and delivering real value.

In a nutshell, SMS is not here to replace your marketing playbook. It’s here to enrich it, with messages your customers actually want to receive and act on.

With our extensive experience and expertise of over a baker’s dozen years in the CRM sphere, we at Mavlers have created a step-by-step guide on maximizing the benefits of Klaviyo’s SMS capabilities to ensure multichannel marketing success.

Step 1: Building your Klaviyo SMS opt-in strategy, weaving permission with personality

If email is the friendly knock on someone’s front door, SMS is walking straight into their living room. That privilege comes with rules, and they’re stricter than most marketers realize. 

Skip them and you don’t just annoy people; you expose the brand to hefty fines and carrier blocks. So, before the first text leaves Klaviyo, nail these four basics:

1. Refresh the privacy policy (yes, today)

Open the doc, hit Edit, and add a plain‑English paragraph that explains:

• why you’re collecting phone numbers
  
• what you’ll text about (promos, order updates, abandoned‑cart nudges, etc.)
  
• how you detect cart abandonment (cookies, plug‑ins, magic elves—spell it out)
  
• how people can opt out at any time
  

Then paste that policy link right on the SMS sign‑up form so nobody has to hunt for it.

2. Remember: phone number ≠ permission

Having a customer’s mobile number on file, whether from customer service or checkout, does not necessarily mean you can text them. You need a separate, explicit opt‑in that reads something like:

“By entering your number, you agree to receive marketing texts from [Brand]. Msg & data rates may apply. Reply STOP to unsubscribe.”

No lawyerly riddles. No grey areas. Just straight talk.

3. Double opt‑in is your safety net

Yes, it adds a step. Yes, it’s 100 % worth it. Double opt‑in filters out typos, bots, and “I‑changed‑my‑mind” sign‑ups, so deliverability stays clean and your list stays engaged.

The easy button?

Klaviyo’s Smart Opt‑in and Tap‑to‑Text forms handle the whole flow:

1. visitor taps the form (no manual typing)
   
2. a pre‑filled text pops up on their phone
   
3. they hit send (“YES”) to confirm, and they’re in
   

It meets carrier requirements and feels effortless for the subscriber.

4. Make opting out painless

Every relationship needs an exit ramp. Add “Reply STOP to unsubscribe, no hard feelings” to the very first SMS, and repeat it about once every fifth message or once a month (whichever comes first). Klaviyo automatically processes the keyword so nobody gets stuck on a list they don’t want.

Here’s the bottom line: compliance isn’t a checkbox; it’s your first promise to the customer. Start with transparency, explicit permission, double opt‑in (made frictionless by Smart Opt‑in and Tap‑to‑Text), and an easy exit. Do that, and every text you send is welcomed, not resented.

Step 2: Grow your SMS list with smart, low-friction sign-up forms

Okay, so you’ve laid the compliance groundwork, great! Now it’s time to actually build your list.

Here’s the thing: people don’t just hand over their phone numbers like they do with email. A phone number is personal. So the key to growing your SMS list isn’t being pushy, it’s being strategic.

Start with your warmest audience

If you already have an email list, that’s your low-hanging fruit. These folks know your brand, they’ve engaged before, and they’re far more likely to opt into text updates, especially if the offer feels relevant and respectful.

The easiest play? Show your SMS sign-up form only to people who are already subscribed to your emails. It’s targeted, it feels natural, and you’re not coming out of nowhere asking for their digits.

Want to cast a wider net? Try shooting a multi-step form.

If you’re looking to grow your list faster, or you’re feeling a little gutsier, you can use a multi-step form. It works like this:

1. Step one: Ask for their email (easy, low commitment)
   
2. Step two: Once they submit, then ask for their phone number
   

It’s a smoother on-ramp. People are far more likely to share a phone number after they’ve already given you something else first.

Sweeten the deal with a little incentive

Phone numbers are valuable, so it makes sense that subscribers want something valuable in return. If you’re asking for both email and SMS, consider stacking your offer:

“10% off when you join our email list and get an extra 5% when you sign up for texts!”

It feels like a bonus, not a bribe. Plus, you’re giving people a real reason to join your SMS list beyond just “updates.”

Here’s a pro tip, Klaviyo’s built-in form builder lets you segment based on list status (like “already on email”) so you’re not asking the same person twice. Less friction ultimately translates into more signups.

Step 3: Ask for SMS consent at checkout when it just makes sense

Checkout is one of the best times to ask for a phone number, as your customer is already providing details like their name, email, and shipping information. At that point, asking for SMS consent feels natural, not intrusive.

And the good news? 

If you’re using Shopify, WooCommerce, BigCommerce, or Adobe Commerce (Magento), Klaviyo makes it incredibly easy to integrate an SMS opt-in checkbox directly into the checkout flow.

Here’s where it gets even better:

The customer doesn’t have to complete their order for the opt-in to count. Yep, you read that right. If someone types in their number and checks the box but then bails on the purchase? You still have their SMS consent.

Which means you can send a well-timed cart reminder later, nudging them back to finish what they started. Smart, right?

Ensure that your opt-in language at checkout is clear and compliant. Something to the tune of:

“Yes, I want to receive order updates and exclusive offers via text. Msg & data rates may apply. Reply STOP to unsubscribe.”

It’s low effort for the customer, high reward for you, and one of the most seamless ways to grow a quality SMS list without disrupting the buying experience.

Step 4: Set up SMS welcome & abandoned cart flows, because first impressions (and forgotten carts) count

If someone’s just given you their phone number, they’re not doing it lightly. They’ve said, “Yes, I want to hear from you.” So now’s your moment to show up with something that feels personal, useful, and worth it.

That’s where your welcome flow and abandoned cart flow come in.

These aren’t just nice-to-haves, they’re your chance to make early connections and recover sales that would otherwise disappear into the void.

SMS welcome flow: Start the relationship on the right foot

The moment someone subscribes to your texts, they should get a message that feels less like a robot and more like a friendly wave.

This is your chance at a great first impression, use it well.

Here’s what to include:

• Your brand name, so they know it’s you
  
• A thank-you for subscribing (people like to be acknowledged)
  
• A quick note about what kinds of texts to expect (promos? order updates? VIP stuff?)
  
• A discount code or incentive (if you promised one)
  
• A clear CTA that links them back to your site
  
• And yes, the STOP-to-opt-out line, right there at the end
  

You know something like:

“Hey! 👋 It’s [Your Brand]. Thanks for signing up! You’ll be the first to hear about special deals + product drops. Use code WELCOME10 for 10% off: [link] 🛒 Reply STOP to opt-out.”

Short, clear, distinctly human. That’s the tone you want.

Abandoned cart flow: A friendly reminder, not a guilt trip

We’ve all done it, filled up our cart, got distracted, and poof, gone.

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In fact, according to the Baymard Institute, over 70% of online shoppers abandon their carts. But with SMS, you’ve got a shot at pulling some of them back.

If you’re already sending cart reminders via email, great, but adding SMS to the mix seriously boosts your odds. Why? Because texts are faster, more immediate, and often get seen within minutes.

Here’s what a great abandoned cart SMS should include:

• Your brand name (again, always)
  
• The customer’s first name if you’ve got it
  
• The product name they left behind
  
• Bonus points for a product image if you’re using MMS
  
• A link back to their cart (pre-filled = zero friction)
  
• Maybe a small discount or offer to sweeten the deal
  
• And the STOP opt-out reminder
  

You could try something like:

“Hey [Name], still thinking about that [Product Name]? It’s waiting in your cart 🛒 Use code SAVE10 before it’s gone: [link] – [Your Brand]. Reply STOP to opt-out.”

Here’s a fun pro tip: if you’re already running email flows in Klaviyo, you don’t need to start from scratch. You can simply clone the existing abandoned cart flow and add SMS as a step alongside the emails. That way, your channels work together instead of competing.

Step 5: Setting the texting cadence ~ Start small, stay consistent, hit the sweet spot!

Let’s clear up one big myth about SMS marketing right now: you don’t need to be texting your audience every week to make it work.

In fact, if you’re just starting, one to four texts per month is a great baseline. Why? Because consistency builds trust, but oversending burns it to the ground. The goal is to become a welcome presence in someone’s messages, not the brand they dread hearing from.

Think of it this way: if email is the newsletter, SMS is the gentle nudge. It’s meant to be punchy, timely, and high-value. If you don’t have something useful, don’t send it just because the calendar says so.

A couple of texts a month is enough to:

• Keep your brand top of mind
  
• Gather early data (what drives clicks, conversions, replies)
  
• Set expectations: “This brand only texts when it matters.”
  

And when you’ve figured out what your audience responds to? That’s when you scale.

What should you actually send?

Honestly, don’t overthink it. The most effective SMS campaigns are concise and relevant. Think back-in-stock alerts, flash sales, “We thought you’d like this.”, quick product drops, and time-sensitive offers.

You don’t need Shakespeare. All you need is clarity and timing.

Klaviyo even offers an SMS AI tool to help generate copy ideas, but let’s be real: it’s a jumping-off point, not a replacement for human tone. You still want the message to sound like your brand, not a robot trying to sell candles.

And yes, there’s a checklist (but keep it natural)

There are some things you absolutely need in every text:

• Your brand name (so people know who it’s from)
  
• A clear, time-sensitive hook (give them a reason to act now)
  
• A short, branded link (Klaviyo lets you customize this)
  
• A STOP-to-opt-out reminder (especially if it’s their first message from you or you haven’t included it in a while)
  

You’ve only got 160 characters in an SMS, so it makes sense to treat them like gold. Chuck the fluff and sound human. And don’t forget, MMS (which allows images and longer messages) can be powerful for product showcases or big promotions, but it also incurs additional costs. Use it when it counts.

The real key? 

Refrain from treating SMS like email. You’re in someone’s pocket. You’re vibrating their phone. That’s a high-trust moment, so make it count.

Step 6: Stop blasting everyone, start segmenting like a pro!

Want to know how most brands mess up SMS? Well, they treat it like email circa 2010,  mass blast, no context, everyone gets the same message.

And then they wonder why people stop opening, stop clicking, or worse, start replying with “STOP.”

SMS isn’t just a shorter version of email. It’s way more personal, way more direct, and way less forgiving when you get it wrong. Also, Klaviyo’s 2025 future of consumer marketing report, confirmed that 74% consumers actually look forward to personalized experiences! 

That’s why segmentation isn’t optional. It’s the thing that keeps your messages relevant, your subscribers engaged, and your unsubscribe rate from tanking.

Now, before you get overwhelmed thinking segmentation is about slicing your list into 47 pieces, relax. You only need a few smart filters to make a big difference.

You may start with this:

1. Your SMS-consented segment (aka: People you actually have permission to text)

This one’s table stakes. Just because someone placed an order or gave you their number doesn’t mean they agreed to receive texts. If they didn’t opt-in, don’t message them. Full stop.

In Klaviyo, you can filter your audience by explicit SMS consent. Use that. Live by that. Build campaigns only for that list. These folks actually want to hear from you. Everyone else? Off limits.

2. Your recently engaged (Last 30 days)

This group is gold.

They’ve clicked a link, replied to a message, or interacted in some way in the last 30 days. In other words, they’re still paying attention.

Want better ROI? These are the people you send sneak peeks, early access, and special drops to. Want higher conversions? Prioritize them over the unresponsive crowd. SMS isn’t about quantity, ultimately it’s about intent.

3. Your SMS errors segment (Yep, that’s a thing)

Nobody talks about this enough. Not every number on your list is functional. Some are dead. Some bounce, while some might even be blocked by carriers.

If you keep sending to them, not only are you wasting money, you’re dragging down your deliverability.

Klaviyo gives you visibility here. You can create segments based on SMS error types and automatically exclude them from campaigns until the issue’s resolved.

It’s cleanup work, but it matters. A messy list hurts your sender reputation. A clean one keeps your delivery rate high, your texts landing, and your brand in good standing with the carriers.

Step 7: Watch your numbers from day one!

You hit send, awesome! But now what?

If you’re not tracking how your SMS campaigns actually perform, you’re flying blind.

Start by checking deliverability. That’s how many texts actually make it to your customers’ phones, not just how many you sent. Aim for 95% or higher. Anything less? Something’s broken, maybe bad numbers, maybe consent issues.

Next, look at your click rates and conversions. Klaviyo’s SMS benchmarks show that good campaigns get:

• Around 5.76% click-through
  
• At least 0.1% placed order rate
  

That might sound small, but with SMS volume, it adds up fast.

Klaviyo’s built-in dashboard makes this easy. You can track list growth, revenue, engagement, and if your messages are actually landing. If you want to go deeper, their SMS Deliverability Hub has you covered.

Bottom line? 

Don’t just send; measure, adjust, and repeat.

That’s how you turn SMS from “meh” into money.

The road ahead

In case you are considering migrating to Klaviyo and would like a fail-safe experience, we recommend reading ~ Klaviyo Migration Checklist: Steps & Best Practices.