How to Migrate to Klaviyo: The Complete Guide

Migrating your email marketing platform is one of the most impactful decisions you can make for your ecommerce business. It is also one of the most daunting. A poorly managed migration can result in lost subscriber data, broken automations, deliverability problems, and weeks of lost revenue.

This guide covers the complete migration process from any email platform to Klaviyo, based on dozens of migrations we have managed through our Klaviyo email marketing services. Follow this process and you will transition smoothly with zero data loss and minimal disruption.

Why brands migrate to Klaviyo

The most common reasons brands migrate to Klaviyo:

• Outgrowing their current platform — Mailchimp, Omnisend, and other platforms have limitations in segmentation, automation, and ecommerce integration that become apparent as brands scale
• Better Shopify integration — Klaviyo's Shopify development integration is significantly deeper than alternatives
• Revenue attribution — Klaviyo's reporting and attribution make it easier to measure email's commercial impact
• Predictive analytics — CLV prediction, churn scoring, and other predictive features are unique to Klaviyo
• Consolidation — Bringing email and SMS onto one platform instead of managing separate tools

Migration planning checklist

Before touching any data, complete this planning checklist:

• Audit your current email programme: how many flows, campaigns per month, and active subscribers?
• Document all flows and their logic (triggers, filters, timing, content)
• Identify all integrations that connect to your current email platform
• Set up your Klaviyo account and configure sender domain authentication (SPF, DKIM, DMARC)
• Determine your migration timeline and choose a low-traffic period for the switch
• Assign a project owner responsible for the migration

Data migration: what to move

Essential data to migrate

Data type	Source	Klaviyo destination
Email addresses + profiles	Export from current platform	Import as profiles with properties
List/segment membership	Export per list	Import to corresponding Klaviyo lists
Consent records	Export timestamps + methods	Import as profile properties + consent fields
Engagement history	Export opens/clicks per contact	Import as custom properties for segmentation
Suppression list	Export all suppressed contacts	Import to Klaviyo suppression list

Data that syncs automatically

Once you connect Klaviyo to Shopify, customer data, order history, and product catalogues sync automatically. You do not need to manually migrate this data. Klaviyo will pull your full Shopify history within hours of connecting.

Data migration process

1. Export all subscriber data from your current platform in CSV format
2. Clean the data: remove duplicates, standardise formatting, verify email addresses
3. Map fields from your current platform to Klaviyo profile properties
4. Import the cleaned data into Klaviyo using the bulk import tool
5. Verify the import: check profile counts, property mapping, and list assignments
6. Import your suppression list to prevent sending to unsubscribed contacts

Rebuilding your flows

Flows do not transfer between platforms. You need to rebuild each flow in Klaviyo's flow builder. This is actually an opportunity to improve your automations, as Klaviyo's flow capabilities are typically more advanced than your previous platform.

Priority order for flow rebuilding

1. Abandoned cart — This is your highest-revenue flow. Rebuild and test it first.
2. Welcome series — Every new subscriber should enter a welcome flow immediately.
3. Post-purchase — Order confirmations and follow-up sequences.
4. Browse abandonment — Re-engage visitors who viewed products.
5. Winback — Re-engage lapsed customers.
6. Additional flows — Cross-sell, replenishment, VIP, etc.

For each flow, document the trigger, filters, timing, and content from your current platform, then rebuild in Klaviyo with improvements. For flow best practices, see our 7 Klaviyo flows guide.

Template migration

Email templates from other platforms rarely transfer cleanly to Klaviyo. The recommended approach is to use this as an opportunity to redesign your templates in Klaviyo's native builder, which ensures compatibility with Klaviyo's dynamic content blocks and rendering engine.

If you have custom HTML templates, they can be imported into Klaviyo, but they will need adaptation to work with Klaviyo's template variables and product blocks.

Protecting deliverability during migration

Deliverability is the biggest risk during a migration. Here is how to protect it:

Domain warming

When you start sending from Klaviyo, you are sending from a new infrastructure. Inbox providers do not yet know your reputation on this new setup. Warm up gradually:

1. Week 1: Send to your most engaged segment only (opened in last 30 days). Start with 1,000 to 2,000 contacts.
2. Week 2: Expand to contacts who opened in the last 60 days. Double your volume.
3. Week 3: Expand to contacts who opened in the last 90 days. Continue doubling.
4. Week 4: Send to your full active list.

Sender authentication

Set up SPF, DKIM, and DMARC records for your sending domain before sending any emails from Klaviyo. This authenticates your emails and tells inbox providers that Klaviyo is authorised to send on your behalf. Klaviyo provides instructions for this in the account settings.

Parallel sending

During the warming period, keep your old platform active for automated flows. Only switch flows to Klaviyo once your Klaviyo sending reputation is established and deliverability metrics are healthy.

Testing before go-live

Before fully switching to Klaviyo, test everything:

• Send test emails for every flow and verify triggers, timing, and content
• Test dynamic content blocks with real customer data
• Verify all links in every email template
• Check email rendering across clients (Gmail, Outlook, Apple Mail, mobile)
• Verify integrations are syncing data correctly (Shopify, review platforms, etc.)
• Test signup forms and verify new subscribers enter the correct lists and flows
• Verify suppression list is working (suppressed contacts should not receive emails)

Migration timeline and milestones

Week	Milestone
Week 1	Account setup, domain authentication, data export from old platform
Week 2	Data import, Shopify connection, template creation, flow building
Week 3	Testing all flows and templates, begin deliverability warming
Week 4	Switch flows to Klaviyo, expand sending volume, monitor deliverability
Week 5	Full migration complete, decommission old platform, post-migration audit

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Migrating to Klaviyo is a significant project, but the long-term benefits — better automation, deeper Shopify integration, predictive analytics, and unified email/SMS — make it worthwhile for virtually every ecommerce brand. The key is planning thoroughly, protecting deliverability during the transition, and using the migration as an opportunity to improve your email programme.

If you want a managed migration with zero downtime and zero data loss, get in touch. We handle the full process through our Klaviyo email marketing services, from planning through to post-migration optimisation. See also our ecommerce migration checklist for the broader platform migration picture.