Email and SMS in the same flow: who gets which, and when

This is for Shopify founders who just turned on SMS in Klaviyo and want to add it to their flows without double-messaging the customers who signed up for both.

How should email and SMS work together in a flow?

Each channel gets a job.

• Email: branding and awareness. The product story, how to use it, why it's made the way it is, the offer explained.
• SMS: reminders. The offer is live, your cart is waiting, the email is in your inbox.

SMS is a more acute form of marketing than email. It's timely and urgent and carries very little brand awareness. Klaviyo's email-and-SMS guide says texts are "seen by almost all recipients," often within seconds. That's a lot of attention. Spend it on the moment that needs a nudge, not on a copy of the email.

So the rule I build to: time it properly. A text that lands minutes after an email with the same message is wasted attention, and it's the kind of thing that gets people to text STOP.

Do SMS subscribers get texts on top of emails or instead of them?

Instead of, at the step where the text goes.

Klaviyo's guide to using email and SMS together says: "Rather than placing an SMS and email directly next to each other in a flow, include splits to send anyone consented to SMS down a different path than those who have only subscribed to email." The same page says "you shouldn't send an SMS for every email you have. Instead, decide which channel to prioritize."

Klaviyo's abandoned cart SMS guide shows how. After the first delay, add a conditional split, "If someone can or cannot receive marketing," set to text message marketing. People who can receive texts get the SMS. Everyone else gets the email. The SMS path rejoins after the first email, so SMS recipients skip that first email and pick up the rest of the email flow.

That's the pattern for almost every flow:

1. Split on SMS consent at the step where a reminder matters most.
2. SMS path: one text.
3. Email path: the email that would have gone out.
4. Rejoin, and everyone continues on email.

SMS subscribers still get most of your emails. They just get one text in place of one email, at the right moment.

Which flows should get SMS first?

The ones where a reminder is the whole job.

• Abandoned cart and checkout. The person was about to buy. One text is the cleanest nudge there is. I cover it step by step in abandoned cart SMS.
• Shipping cutoffs. I send at least one text on cutoff day or the day before. With spare budget, one a week or two ahead, then more as the date gets close. More in my holiday shipping cutoff email post.
• Post-purchase upsell. No less than 2 weeks after the order. See my SMS post-purchase upsell.

Klaviyo's best practices page lists abandoned cart among the flow messages in its suggested monthly SMS mix, and suggests 1 to 2 texts a week in total. Count your flow texts in that number.

Flows I'd keep on email: the ones that are mostly story and education, like most of a welcome series. The welcome email series is where you explain the brand. That's email's job.

If you've just turned SMS on, start with your highest-leverage marketing and see what works before you add texts everywhere.

How do you stop someone getting an email and a text about the same thing?

Three things.

1. Use the split, not side-by-side steps. In flows, the consent split above means a person gets one or the other at that step, never both.

2. In campaigns, send the text first and exclude the overlap. Klaviyo's email-and-SMS guide says to send the SMS campaign several hours or days ahead of the email, and to exclude the SMS segment from the email. Its words: "If you don't exclude this group, anyone with consent for both SMS and email will get the message twice." Klaviyo's best practices page gives an example: text SMS subscribers at 10 a.m., email the SMS subscribers who didn't click at 1 p.m., and email everyone without SMS consent at 1 p.m. It also notes "SMS tends to perform better when sent before email."

3. Make the text a reminder of the email, not a copy of it. "Your guide to [product] is in your inbox" is a different message from the guide itself.

How many texts should one flow have?

One per person, in most flows.

I only use one-step flows for SMS. In email, I'm happy to run long flows. In SMS, the text should be as pointed as possible, especially in abandoned checkout.

For abandoned cart flows in the US, it's not just my preference. Klaviyo's abandoned cart SMS guide lists US requirements: double opt-in for SMS consent, only 1 SMS per recipient, and send within 48 hours of the cart being abandoned. Klaviyo's compliance page says applying those to other abandonment flows is a best practice, though carriers don't require it.

How do quiet hours and Smart Sending affect a mixed flow?

Quiet hours. Klaviyo's quiet hours page says to send in the recipient's local time and, in general, avoid before 8 a.m. and after 9 p.m. A text that hits quiet hours waits in the flow until a permitted time. Klaviyo's other pages are stricter. Its best practices page says avoid before 9 a.m. or after 8 p.m., and its compliance page notes some US states, like Florida, limit sending to 8 a.m. to 8 p.m. I build to the stricter window. Quiet hours are on by default for SMS, and Klaviyo doesn't recommend turning them off.

That matters in a mixed flow because the text quiet hours apply to the text. If a text step comes due late at night, it waits until morning while the email path keeps moving. Check your delays with that in mind so the two paths don't drift apart.

Smart Sending. Klaviyo's quiet hours page explains that quiet hours are checked first, then Smart Sending, and if not enough time has passed since the last message, Klaviyo skips it. I keep Smart Sending off on automations so people don't miss critical reminders. In a mixed flow, Smart Sending on can quietly skip the one text you placed on purpose. More on that in Klaviyo Smart Sending.

What about consent?

This is general information, not legal advice.

You need SMS marketing consent before any marketing text. Klaviyo's best practices page says agreeing to email, general marketing or one-time transactional SMS "isn't enough." And Klaviyo's compliance page says consent for order updates doesn't subscribe someone to marketing texts.

I run single opt-in for email and double opt-in for SMS. SMS is a more acute form of marketing, so commitment to the list matters more. For abandoned cart texts in the US, Klaviyo lists double opt-in as a requirement anyway. More in SMS marketing consent for Shopify.

What should a founder with a new SMS list change first?

1. Turn off any flow step where an SMS and an email sit next to each other. Replace it with a consent split.
2. Add one text to your abandoned cart or checkout flow. One text, after the first delay.
3. Exclude SMS subscribers from the email when a campaign also goes by text. Send the text first.
4. Check quiet hours are on and Smart Sending is off for the flows with texts.

For how all your flows fit together, see Klaviyo flows for CPG brands, and for the email side of the checkout flow, my abandoned checkout email guide.

FAQ

WRITTEN BY Jack White

Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.

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