When to Add SMS to Klaviyo (and When to Hold Off)

A text lands differently than an email. It buzzes in someone's pocket, mid-dinner, mid-meeting, and most people read it within minutes. That's the appeal. It's also the reason to be careful.

SMS can be a real part of a retention system. Klaviyo runs email and SMS side by side, so adding it is technically easy. Whether you should add it yet is a different question, and for a lot of Shopify brands the honest answer is not quite yet.

Here's how to tell which side you're on.

Why the bar for SMS is higher

Email and SMS work differently, and a few things make SMS a bigger commitment.

It's intimate. A text goes to someone's phone, the same place their family and friends text them. That earns attention, and it wears out fast if you misuse it.

It's interruptive. An email waits politely in an inbox. A text interrupts. Get the timing or the frequency wrong and people opt out quickly, or worse, start resenting you.

It costs per message. Klaviyo SMS runs on credits, so every send has a real cost attached. Blasting your whole list a text that doesn't land is more expensive than the email version of the same mistake.

It's regulated. SMS has real consent and compliance rules. You need clear, explicit opt-in, and there are legal requirements about how and when you can text people. This part isn't optional.

So SMS is worth adding. Just add it on purpose, when it's going to earn its place.

Signs you're ready

A few things tell me a brand is ready to add SMS.

Your core email flows are already built and working. Welcome, abandoned cart, post-purchase, the basics that catch people at the big moments. SMS works best layered on top of a system that already runs. If you haven't built those yet, that's the first job, and it's exactly what the core Klaviyo flows are for.

You have the volume to justify it. Enough traffic and enough buyers that the setup, the consent collection, and the per-message cost are worth it. A brand getting a trickle of orders a month has bigger things to build first.

You have moments that genuinely deserve a text. Order and shipping updates. Back-in-stock alerts on something people actually wait for. A cart reminder. A real, time-limited drop. These are the moments where a text beats an email, because speed and immediacy matter.

You can handle the consent and compliance part. You're set up to collect proper opt-in and you're willing to stay on the right side of the rules.

Signs you should hold off

The other side is just as clear.

Your email program isn't built yet, or isn't working. Adding SMS on top of weak email won't fix anything. You'll just pay more to reach people in a more intrusive way. Build the email foundation first, then layer SMS on.

Your list is tiny. If you've got a small handful of subscribers and a few orders a month, the cost and effort of standing up SMS won't pay off yet. Grow the base first.

You'd only use it to blast promos. If your plan for SMS is the same "20% off" you already email, to the same people, you'll burn out the audience fast. People tolerate a lot more in their inbox than on their phone. A text that's just another discount is the quickest way to get someone to opt out, and it leans on the discount habit you don't want to build anyway, which is the whole argument in why discounts train your list to wait.

You can't keep up with compliance. If proper consent and the legal side are more than you can manage right now, hold off until you can. The downside isn't worth it.

What good SMS looks like when you do add it

Start small and high-value. Turn on the texts that are genuinely useful first: order and shipping confirmations, back-in-stock, a cart nudge. Add promotional texts sparingly, for moments that actually matter.

Keep them short and timely. A text earns its buzz by being worth the interruption. If you wouldn't want to receive it mid-dinner, don't send it.

Let email and SMS each do what they're good at. Email carries the longer story, the teaching, the browse-and-click. SMS carries the urgent and the time-sensitive. Together they cover more than either does alone, without doubling up on the same message.

When this isn't your problem

If your email program is humming and you've got real moments worth a text, SMS is a strong next move, and Klaviyo makes running both together straightforward.

If your email is still shaky, SMS will feel like an upgrade and won't act like one. It's one more thing to manage and pay for, sitting on a foundation that still needs the work. There's no prize for adding SMS early. The brands that get the most out of it added it when they were ready.

Before you turn on SMS

• Are your core email flows built and actually working?

• Do you have the traffic and order volume to justify the setup and per-message cost?

• Do you have specific, time-sensitive moments where a text genuinely beats an email?

• Can you collect proper opt-in and stay compliant with SMS rules?

• Is your plan for SMS more than blasting the same discounts you already email?

SMS is a real addition to a retention system, once the system is ready for it. Get your email working first, then add SMS when you've got moments worth the buzz and the base to support it. Bring it in at the right time and it earns its place.

If you're weighing whether SMS makes sense for your brand yet, or trying to get your email working before you add anything, book a free call. We'll talk through where your program is now and whether working together makes sense. No pressure, no pitch.

Email is a system, not a send.

— Alex

Need help implementing these strategies in your email marketing program?

Frequently asked questions

Should I add SMS to my Klaviyo account?

Add it once your core email flows are built and working, you have enough traffic and orders to justify the per-message cost, and you have specific time-sensitive moments worth a text, like shipping updates, back-in-stock alerts, or cart reminders. If your email program isn't built yet or your list is small, build email first and hold off on SMS.

Is SMS better than email for ecommerce?

Neither is better; they do different jobs. Email carries the longer story, teaching, and browsing, and costs little per send. SMS is immediate and gets read fast, but it's more intrusive, costs per message, and has strict consent rules. The strongest programs use both, each for what it does well, rather than picking one.

Do I need consent to send SMS in Klaviyo?

Yes. SMS requires clear, explicit opt-in before you can text someone, and there are legal rules about how and when you send. Klaviyo gives you compliant signup tools, but the responsibility to collect proper consent and follow the rules is yours. Don't treat email and SMS consent as interchangeable; SMS is stricter.