Klaviyo is the gold standard for e-commerce email and SMS. If you run an online store and have outgrown Mailchimp's basic segmentation and automation, Klaviyo is the most common next step.
This guide covers everything you need to migrate from Mailchimp to Klaviyo without losing subscribers or breaking your automations. Estimated time: half a day.
What transfers and what does not
| Item | Transfers? | Notes |
|---|---|---|
| Contacts and email addresses | Yes | Via CSV export/import |
| Tags and segments | Partial | Export as custom fields, remap on import |
| Custom field data | Partial | Transfers if mapped correctly during import |
| Unsubscribe history | Yes | Import as suppressed contacts |
| Email templates | No | Need to be rebuilt in Klaviyo |
| Automation workflows | No | Need to be rebuilt from scratch |
| Campaign history | No | Historical stats stay in Mailchimp |
Step-by-step migration guide
Sign up at www.klaviyo.com before doing anything else. Keep your Mailchimp account running throughout the migration: do not cancel it until everything is confirmed working in Klaviyo.
Add your domain to Klaviyo and follow the DKIM authentication instructions. This improves deliverability and ensures your emails arrive in inboxes, not spam folders. Complete this before importing any contacts.
In Mailchimp, go to your audience and export your full contact list as a CSV. Make sure to include all custom fields, tags, and segments. Export your unsubscribed contacts separately: you will need to suppress these in Klaviyo to stay compliant.
Upload your CSV into Klaviyo and map each column to the correct field. Import your unsubscribed contacts as suppressed. Review the import report carefully before proceeding: fix any mapping errors before building automations.
Screenshot or document all your active automations in Mailchimp before rebuilding them in Klaviyo. Start with your highest-priority flows: typically your welcome series and any active nurture sequences. Do not activate them until you have tested them with your own email address.
Build your signup forms in Klaviyo and replace the Mailchimp embed codes on your website. Test each form to confirm subscribers land in the right list and trigger the correct automation.
Send a test campaign to yourself. Trigger your automations manually. Check every link. Confirm your unsubscribe flow works correctly. Only cancel Mailchimp once you are fully satisfied that Klaviyo is working as expected.
Once Klaviyo is fully operational, cancel your Mailchimp account. Check your billing date to avoid being charged for another month. Download any historical reports or data you want to keep before cancelling.
The bottom line
If you run an e-commerce store and need real revenue attribution, advanced segmentation, and SMS alongside email, Klaviyo is worth the migration. The setup takes longer than simpler tools but the capabilities justify it.
Not sure Klaviyo is the right destination? Take the Marketing Automation Buyer's Guide quiz for a personalized recommendation.