Moving from Mailchimp to Klaviyo: A Practical Migration Guide

Businesses usually move from Mailchimp to Klaviyo for one reason: Klaviyo is built around ecommerce, so it ties directly into your store, attributes revenue to individual emails, and lets you segment on real purchase behaviour rather than broad lists. The pull is understandable. The move itself is straightforward as long as you treat it as a migration of several things — not just a list of email addresses — and protect the two assets that are easy to damage: your subscribers' consent and your sending reputation. Here is what the switch actually involves.

What Actually Needs to Move

The email address list is the obvious part, but a Mailchimp account holds more than that, and each piece needs a plan:

• Your audience and their consent status — who is subscribed, who has unsubscribed, and who never opted in.
• Segments and tags — the groupings you use to target the right people.
• Templates and branding — your email designs, which do not transfer automatically.
• Automations — welcome sequences, abandoned-cart, and post-purchase flows.
• Signup forms and popups — the ways people join your list.

Only the first of these truly "moves"; most of the rest is rebuilt in Klaviyo, which is a good opportunity to improve on what you had rather than copy it across verbatim.

Migrating Your Audience (and Consent)

Export your contacts from Mailchimp and import them into Klaviyo — but the critical detail is preserving subscription status. Bring across who is subscribed and, crucially, keep unsubscribed and cleaned contacts marked as such so you never email someone who opted out. Emailing people who previously unsubscribed is both a compliance problem and the fastest way to wreck your deliverability. Import the subscribed audience, keep the suppression list suppressed, and resist the temptation to "start fresh" by re-emailing everyone. Getting consent right at this stage is the whole game; if you run email and SMS together, the same discipline applies, which we cover in combining Klaviyo email and SMS into a single flow.

Rebuilding Flows and Templates

Your Mailchimp automations do not carry over, so plan to rebuild them in Klaviyo — the welcome series, abandoned-cart, browse-abandonment, and post-purchase flows. This sounds like a chore but is actually where Klaviyo earns its keep, because its flows can trigger on store events Mailchimp cannot see. Recreate your templates to match your branding while you are at it. Because this is a rebuild, it pays to prioritise: get the highest-value flows (welcome and abandoned-cart) live first, then work down. If you are weighing the two platforms in the first place, our Klaviyo vs Mailchimp for Shopify comparison lays out the trade-offs.

Deliverability: Don't Skip This

The single most common way a migration goes wrong is deliverability. When you start sending from a new platform, mailbox providers do not yet trust it with your domain. Authenticate your sending domain in Klaviyo (DKIM and the related DNS records) so your mail is properly signed, and warm up by sending to your most engaged subscribers first before ramping to the full list — a sudden blast from a cold setup lands in spam. Keep the list clean by leaving unengaged and invalid addresses behind rather than dragging them across. Do this properly and your open rates hold through the switch; skip it and you can spend weeks digging out of the spam folder.

Getting Help

Moving from Mailchimp to Klaviyo is well worth doing for an ecommerce business, and it goes smoothly when it is treated as a proper migration — audience and consent first, flows and templates rebuilt second, deliverability protected throughout. If you would like it done without the risk to your list or your reputation, our Email Marketing service handles the migration end to end and rebuilds your flows to actually use Klaviyo's strengths. Switch platforms, keep your subscribers and your inbox placement, and come out the other side sending smarter email.