Klaviyo Migration for Shopify Brands: The Shopify-Specific Steps Most Guides Miss

Direct answer: Klaviyo migration for Shopify brands has several Shopify-specific requirements that don't appear in generic migration guides: disconnecting the old ESP from Shopify before connecting Klaviyo, adding a flow filter to the welcome series to exclude checkout subscribers who have already placed an order, mapping Shopify customer tags to Klaviyo for segment continuity, and verifying that the Checkout Started event fires at the correct point in custom or extended checkout flows. Sticky Digital, a Klaviyo Platinum Partner and Retention Marketing Agency of the Year, builds these Shopify-specific steps into every migration rather than discovering them after go-live.

Why Shopify Migrations Have Shopify-Specific Problems

The generic Klaviyo migration guide covers authentication, suppression import, list migration, flow rebuild, and warm-up. All of that applies to any ESP migration. What it doesn't cover is the Shopify integration layer — the specific way Klaviyo and Shopify share subscriber data, checkout events, and customer profile information — and the ways that integration layer creates problems unique to brands moving off a Shopify-connected ESP.

Shopify brands face a specific migration complexity: both the old ESP and Klaviyo connect to Shopify at the integration level, and if that integration isn't managed in the correct sequence, things that shouldn't happen start happening. Subscribers receive emails from two platforms. Opt-in confirmations arrive twice. Welcome flows trigger for customers who just purchased. These aren't generic migration mistakes — they're Shopify integration sequencing errors that look like platform problems but are actually configuration problems.

The Old ESP Disconnect Problem

When a brand migrates from Mailchimp, Omnisend, or any other ESP that was connected to Shopify, that old integration stays active until someone explicitly disconnects it. The old ESP continues receiving subscriber signals from Shopify — new checkouts, email subscriptions, form fills — as long as the Shopify integration remains connected.

The migration sequence that produces the problem: brand connects Klaviyo to Shopify while the old ESP integration is still active. Both integrations receive the same subscriber events from Shopify. Both integrations process those events. If the old ESP has a double opt-in confirmation enabled, it sends a confirmation email. If Klaviyo's new list also has double opt-in enabled, it sends a second confirmation email. The subscriber receives two confirmation emails from the same brand within minutes of each other — one from the old platform, one from the new one.

A home goods brand we worked with made this mistake during a migration from Mailchimp. Both integrations were active for three days before the issue was identified. During that window, new subscribers who signed up through their Shopify checkout received confirmation emails from both Mailchimp and Klaviyo — two separate "Please confirm your subscription" emails from the same brand. Twelve percent of those subscribers unsubscribed from one or both platforms in response. The brand's customer service team received support tickets asking why they were sending duplicate emails. The Mailchimp integration was disconnected on day four, but the damage to those subscriber relationships was already done.

The fix is straightforward and must happen before connecting Klaviyo: disconnect the old ESP's Shopify integration completely before authorizing the Klaviyo integration. Verify the old integration is inactive by checking the old platform's integration settings and confirming no new Shopify subscriber events are syncing. Only then connect Klaviyo to Shopify. This sequencing prevents both platforms from acting on the same subscriber events simultaneously.

The Checkout Subscriber Welcome Series Collision

Shopify collects email subscribers at checkout — customers who check the "Subscribe to newsletter" box while completing a purchase. When Klaviyo's Shopify integration is active and this list is connected to a welcome series, those checkout subscribers enter the welcome flow immediately after subscribing. This includes the full welcome sequence: brand introduction, first-purchase discount code, best-seller showcase.

The problem: these subscribers just made a purchase. They receive the first-purchase discount code 24 hours after buying something at full price. Some customers use the code on a subsequent purchase, which is fine. Many find it frustrating. Some email asking for a refund of the discount they didn't know was coming. Revenue attribution from the welcome series looks inflated because it's capturing revenue from people who already intended to purchase again, not driving new purchase intent.

Klaviyo's documentation is direct about this: "Klaviyo's ecommerce integrations are not set up to exclude purchasers who subscribe at checkout from entering a welcome flow. If you want to exclude these profiles from triggering your Welcome Series, add a filter 'Placed Order zero times over all time' to your flow."

That filter is not added by default. It belongs in the welcome series flow filter settings before any subscriber reaches email one of the sequence. For Shopify brands where checkout is a primary subscription method — which is most Shopify brands — this is not an optional configuration. It's the difference between a welcome series that develops relationships with genuinely new subscribers and one that annoys recent purchasers with introductory content and discount codes they can't retroactively apply.

A related configuration: if the brand's welcome series offers a significant incentive in email one (10% or 15% off), consider whether checkout subscribers should enter a different version of the welcome sequence that acknowledges they've already purchased — or a post-purchase flow instead of a welcome flow. The two sequences serve different relationships, and routing checkout subscribers into the wrong one from day one creates a data problem that compounds over the life of the program.

Shopify Customer Tags: Data That Needs to Follow the Migration

Shopify stores use customer tags extensively — VIP, wholesale, loyalty tier, retail partner, press, staff, subscription status, and dozens of custom tags that describe customer relationships the brand has built over years. These tags live in Shopify and sync to Klaviyo as a profile property called "Shopify Tags."

The migration consideration: Klaviyo receives Shopify customer tags as a profile property, which means you can build Klaviyo segments based on Shopify tag values — "Klaviyo profile where Shopify Tags contains VIP" or "Klaviyo profile where Shopify Tags contains wholesale." This is functional, but it depends on the Shopify integration being active and the tags being current when subscriber profiles sync to Klaviyo.

During migration, verify two things. First, confirm that subscriber profiles in Klaviyo are displaying Shopify Tags correctly by spot-checking known VIP or wholesale customers and verifying their tags appear in the Klaviyo profile. Second, understand that Shopify Tags in Klaviyo update when the integration syncs — if a customer is tagged in Shopify, their Klaviyo profile won't reflect that tag until the next sync event. For active brands with high tagging velocity, this sync delay can mean segments built on Shopify Tags are slightly behind the actual tag state in Shopify.

For brands that have built complex customer segmentation around Shopify tags — particularly those with wholesale or B2B customer segments that shouldn't receive retail marketing emails — verify this segmentation is correctly reproduced in Klaviyo before any campaign goes out post-migration. A wholesale customer who was excluded from retail campaigns in Mailchimp via a tag needs to be excluded in Klaviyo via the same tag before the first send.

The Checkout Started Event on Custom and Extended Checkouts

Klaviyo's abandoned checkout flow triggers on the Checkout Started event. For standard Shopify checkout, this event fires after a customer fills out their email address — meaning Klaviyo can associate the event with a subscriber profile and queue the abandoned checkout flow if they don't complete the purchase.

For Shopify stores with custom checkouts — built on Checkout Extensibility, with customized checkout steps, or with multi-page checkout configurations — the Checkout Started event timing can vary. Klaviyo's documentation notes: "If you've customized your checkout, customers may still need to progress to the next step in the checkout process for the Checkout Started event to be triggered."

For brands with custom checkout steps or extended checkout flows (split payment, gift message, upsell steps), test the Checkout Started event timing specifically before activating the abandoned checkout flow. The test: have a known email address proceed through checkout to the point where the event should fire, then check the Klaviyo metric stream for a Checkout Started event associated with that profile. If the event isn't appearing, or if it's appearing earlier than expected (before the email address step), the abandoned checkout flow will either not trigger or trigger without a profile to associate with — resulting in underperformance that's blamed on the category rather than the integration configuration.

How Sticky Digital Approaches Shopify-Specific Migration

When we run a Klaviyo migration for a Shopify brand, the Shopify-specific steps are named checklist items, not assumptions. The old ESP integration is disconnected from Shopify before Klaviyo connects — we verify this by checking the old platform's integration settings and confirming no new subscriber events are syncing before authorizing the new connection.

The welcome series receives its "Placed Order zero times over all time" flow filter before go-live. We also review the welcome series content for first-purchase incentives and confirm whether checkout subscribers should enter a modified version of the sequence or be routed to the post-purchase flow entirely — a decision that depends on the brand's average customer journey and what percentage of list growth comes through checkout vs. organic sign-up.

We audit Shopify customer tags during the migration and build the equivalent Klaviyo segments before the first send. For brands with wholesale, B2B, or loyalty tier segments built around Shopify tags, we verify those tags are appearing correctly in Klaviyo profiles and confirm that suppression or exclusion logic is working before anything goes out to the full list.

The Checkout Started event is tested on a real browser session before the abandoned checkout flow activates — particularly for brands with Checkout Extensibility or custom checkout steps. If the event is firing at the wrong point in the checkout flow, we diagnose and resolve it before the flow goes live rather than after abandoned checkout performance data reveals the problem months later.

More on our approach to Shopify-specific migration is at the Sticky blog. Our migration and onboarding services include the full Shopify integration layer alongside suppression, flow rebuild, and warm-up management. If your brand is on Shopify and you're planning a Klaviyo migration, start a conversation here.

FAQ

Do I need to disconnect my old ESP from Shopify before connecting Klaviyo?

Yes. If your old ESP is integrated with Shopify and you connect Klaviyo without first disconnecting the old integration, both platforms will receive subscriber events from Shopify simultaneously. If either platform has double opt-in enabled, subscribers will receive confirmation emails from both. This is specifically called out in Klaviyo's integration documentation as a known risk: disconnect the old ESP from Shopify before connecting Klaviyo to Shopify. Verify the old integration is fully inactive before proceeding.

Why are customers who purchased at checkout entering my Klaviyo welcome series?

Because Klaviyo's Shopify integration is not configured by default to exclude checkout purchasers from welcome flows. When a customer checks the "Subscribe to newsletter" box at checkout, they're added to the list that triggers the welcome series — even though they've just placed an order. Add a flow filter to your welcome series: "Placed Order zero times over all time." This filter prevents subscribers who have already purchased from entering a welcome sequence designed for new leads. Without it, recent purchasers receive the full welcome series, including any first-purchase discount codes, which is a poor experience and skews welcome series revenue attribution.

Do Shopify customer tags sync to Klaviyo during migration?

Yes. Shopify customer tags sync to Klaviyo as a profile property called "Shopify Tags," which can be used in Klaviyo segment filters. Verify that existing customer tags are appearing correctly in Klaviyo subscriber profiles by spot-checking known tagged customers before building segments around those tags. For brands with wholesale, B2B, or loyalty-tier segments built around Shopify tags, confirm that the corresponding Klaviyo segments are correctly excluding those customers from inappropriate campaigns before the first post-migration send.

What's the difference between migrating to Klaviyo from a Shopify-connected ESP vs. a standalone ESP?

When migrating from a Shopify-connected ESP — Mailchimp, Omnisend, or any platform with an active Shopify integration — the migration includes a Shopify integration layer that doesn't exist when migrating from a standalone ESP. This layer adds the old ESP disconnect requirement, the checkout subscriber routing decision, the Shopify customer tag audit, and the Checkout Started event timing verification. Migrations from ESPs without Shopify integrations don't require these steps because there's no shared integration to coordinate. The technical migration steps (authentication, suppression, list import, flow rebuild) are the same regardless.

Does Klaviyo's Shopify integration work with one-page checkout?

Yes. Klaviyo confirmed compatibility with Shopify's one-page checkout in their integration documentation. The Checkout Started event fires after the customer fills out their email address, regardless of whether you're using one-page or multi-page checkout. The timing consideration applies specifically to custom checkout builds using Checkout Extensibility or non-standard checkout steps — for those configurations, test the event timing specifically before activating your abandoned checkout flow.

Shopify Changes the Migration Sequence

Generic Klaviyo migration guidance covers the core steps correctly. What it misses is the Shopify integration layer — the platform handoffs, subscriber routing decisions, and data sync behaviors that are specific to how Klaviyo and Shopify share information. Getting those right doesn't require unusual expertise. It requires knowing they exist and building them into the migration plan before anything goes live rather than discovering them through subscriber complaints and flow performance data.

If you're on Shopify and planning a Klaviyo migration, we're easy to reach.

Article By: Mariel Kilroy, Co-Founder, Sticky Digital

Mariel Kilroy is the Co-Founder of Sticky Digital, a retention marketing agency specializing in email, SMS, loyalty, and subscription growth for DTC brands.