Here’s a scenario that plays out on a lot of Shopify stores without anyone quite noticing: a customer abandons their cart, gets an email twenty minutes later, then a text an hour after that saying almost the exact same thing, then another email the next day reminding them again. Nothing about that sequence is broken individually, the email flow works, the SMS flow works, but together they feel like two systems that don’t know about each other, because that’s exactly what they are.
This is the most common failure mode once a Shopify store adds SMS on top of an existing email programme: both channels were built as separate flows, each optimising for its own conversion, with no shared logic about who’s already been messaged, through which channel, or how recently. The fix isn’t complicated in concept, treat email and SMS as one coordinated customer journey, but it does require rethinking how your flows are structured in Klaviyo, not just adding an SMS flow alongside your existing email flows.
Why Separate Channel Strategies Break Down
When email and SMS flows are built independently, three problems show up consistently:
- Message fatigue from combined frequency. A customer might unsubscribe from email at a fine frequency and separately opt out of SMS at a fine frequency, but the two channels combined push them well past their actual tolerance for how often they want to hear from you.
- Redundant messaging. The same abandoned cart, the same discount code, the same “last chance” framing arriving through two channels within hours of each other reads as either careless or, worse, slightly manipulative, like you’re trying twice as hard to extract the same sale.
- Inconsistent offers. If your email flow offers 10% off and your SMS flow (built by a different person, at a different time, without cross-checking) offers 15%, customers who receive both notice, and it trains them to wait for whichever channel gives the better deal.
The Core Principle: Design the Journey, Then Assign Channels
Instead of building “the email flow” and “the SMS flow” as two separate projects, map out the actual sequence of touchpoints a customer should experience after a trigger event (cart abandonment, browse abandonment, post-purchase), and then decide which channel is best suited to each touchpoint based on its function, not duplicate the same touchpoint across both.
A practical way to think about channel assignment:
- Email suits messages with more content, more persuasion, or more visual product presentation, a full cart reminder with images, a “customers also loved” cross-sell, an educational touchpoint
- SMS suits short, time-sensitive, high-urgency nudges, a reminder that a cart is about to expire, a flash sale ending in hours, a shipping confirmation
Rebuilding an Abandoned Cart Journey as One Coordinated Sequence
Here’s what a coordinated (rather than duplicated) cart abandonment sequence looks like in practice:
- Hour 1, Email. Full cart reminder with product images, in case it was simply forgotten.
- Hour 4, SMS (only if the customer hasn’t clicked through or purchased from email 1, and only if they’ve opted into SMS). Short, direct: “Still thinking it over? Your cart’s waiting, [link].” No repeat of the full product list; the email already covered that.
- Day 1 (24 hrs), Email. Social proof or objection handling, reviews, a returns/guarantee reminder, genuinely different content from email 1, not a repeat.
- Day 2, SMS (again, only for non-converters, and with a cap on total SMS sends per week regardless of how many flows are technically eligible to fire). This is typically where a time-limited incentive appears, if you’re using one.
The key structural change from a naive “email flow + SMS flow” build: each subsequent message only fires if the customer hasn’t already converted or engaged, and the content is sequenced so nothing repeats verbatim across channels.
How to Build This in Klaviyo
Klaviyo supports mixed-channel flows natively, you can add both email and SMS actions within the same flow, with conditional logic between them, which makes coordinated sequencing achievable without stitching together two disconnected flows manually.
Practical setup steps:
- Use conditional splits based on engagement, not just time delays, e.g. “has this profile clicked the previous email?” before deciding whether the next step is another email, an SMS, or nothing.
- Set a global frequency cap across both channels combined, not just per-flow. Klaviyo’s smart sending settings can suppress a send if a profile has received too many messages recently, configure this at the account level, not just within individual flows, so email and SMS caps interact correctly.
- Consolidate discount logic. If multiple flows can offer a discount, make sure they reference the same offer and expiry rather than independently-set values that can conflict.
- Respect channel-specific opt-in status. A customer might be subscribed to email but not SMS, or vice versa, build your flow logic so it gracefully skips a channel the customer hasn’t opted into, rather than assuming both are always available.
- Review flow overlap regularly. As stores add more flows over time (welcome series, cart abandonment, browse abandonment, post-purchase, win-back), it’s easy for a customer to become eligible for several simultaneously. Periodically audit which flows can trigger concurrently for the same customer.
A Practical Coordination Checklist
- [ ] Map your customer journey by trigger event first, channel assignment second
- [ ] Confirm no two channels repeat the same content or discount within the same journey
- [ ] Set a combined email + SMS frequency cap at the account level
- [ ] Use engagement-based conditional splits rather than blind time-delay sequencing
- [ ] Audit for flow overlap, can a customer be in cart abandonment, browse abandonment and a welcome series simultaneously?
- [ ] Confirm discount codes and expiry dates are consistent across every flow that can surface them
When This Is Worth Bringing in Specialist Help
Mixed-channel flow logic in Klaviyo is genuinely more complex to build and maintain than single-channel flows, particularly once a store has more than a handful of active flows layered on top of each other. The most common outcome we see in stores that built email and SMS separately over time isn’t that either channel performs badly on its own, it’s that combined, they’re working against each other without anyone noticing until list churn or opt-out rates start climbing. This is exactly the kind of cross-flow audit and rebuild our Klaviyo email marketing service handles for growing Shopify stores.
FAQ
Can Klaviyo combine email and SMS in a single flow?
Yes, Klaviyo supports adding both email and SMS actions within one flow with conditional logic between them, which is the recommended approach over building two entirely separate flows for the same trigger event.
How do I stop customers getting both an email and an SMS with the same message?
Build conditional logic that checks whether the customer engaged with the earlier step before sending the next one, and make sure each step’s content is genuinely distinct rather than repeating the same offer or copy across channels.
What’s a reasonable combined email and SMS frequency for a Shopify store?
There’s no single right number since it depends on your industry and audience, but the key principle is capping combined frequency across both channels together, not setting separate caps per channel that can still add up to more total contact than customers want.
Should SMS repeat the discount code from the email in the same flow?
Generally no, if the same flow already surfaced a discount by email, the SMS step should either reference the same code as a reminder (not a new, different offer) or serve a different purpose entirely, like a shipping update or stock alert, rather than pushing the identical offer twice.
How do I know if my email and SMS flows are conflicting?
Signs include rising unsubscribe or opt-out rates without a clear single cause, customers replying confused about receiving multiple similar messages, or an audit showing several flows can trigger for the same customer within a short window. A flow-by-flow audit against actual send logs is the reliable way to check.
Ready to Coordinate Your Channels Properly?
If your email and SMS flows were built at different times by different people, there’s a good chance they’re not talking to each other the way they should be. Book a call and we’ll map your current flows and show you where the overlap is costing you.
