Mailchimp to Klaviyo Migration, Without Breaking Anything
Most brands still on Mailchimp aren't there because they love it. They're there because migrating from Mailchimp to Klaviyo looks like a risk: lost contacts, broken automations, a bruised sender reputation, and weeks of email revenue on the line. It is a risk, if you treat it as a CSV export. We treat it as an engineering job. Audit what you have, move the data Klaviyo can take, rebuild what it can't, test it on dummy profiles, then cut over in the right order. Done for you, fixed scope, fixed timeline.
Still comparing? Read Klaviyo vs Mailchimp →
/ Free Audit
Get your free migration audit
Drop your store URL and email. We'll review your email program and send a written 90-day revenue roadmap within 24 hours. No obligation.
Trusted by
800+ brands
Why brands move from Mailchimp to Klaviyo.
Mailchimp added ecommerce. Klaviyo was built on it.
Credit where due: Mailchimp now has an official Shopify app, predicted customer lifetime value and if/else branching in its automation flows (Standard plan and up). The gap is depth. Klaviyo keeps one profile per person with every order, product view and custom event attached, and every flow filter, split and segment can read from all of it.
Mailchimp bills you for people you cannot email
Mailchimp counts subscribed, unsubscribed and non-subscribed contacts toward your plan limit. Only cleaned (bounced) addresses fall off. Klaviyo bills on active profiles: suppressed and unsubscribed profiles don't count. A big list with a long tail of unsubscribes is paying for dead weight on Mailchimp.
Segments built on events, not tags
On Mailchimp, ecommerce segmentation tends to end up living in tags someone has to maintain. Klaviyo segments update themselves from profile properties, order and browse events, and predictive fields like predicted CLV, churn risk and expected next order date.
Reporting built around revenue
Klaviyo reports revenue per recipient, attributed orders and each flow's share of email revenue, in the same place you build the flows. That's the number we engineer against. Opens and clicks are instruments, not the destination.
What migrates from Mailchimp, and what gets rebuilt.
Item by item. Some of your Mailchimp account moves across, some moves with manual work, and some has to be rebuilt in Klaviyo. Knowing which is which before you start is most of the job.
-
Contacts and audiences
MigratesKlaviyo's built-in Mailchimp integration pulls names, email addresses and locations, and turns each Mailchimp audience into a Klaviyo list. Contacts keep the subscription status they had in Mailchimp, unless the profile already exists in Klaviyo.
-
Unsubscribes and cleaned (bounced) addresses
MigratesSynced and added to your Klaviyo suppression list. Catch: a profile that was already active in Klaviyo before you connect Mailchimp is not suppressed, even if Mailchimp cleaned it. We check for these before the first send.
-
Engagement history
Partly / manualThe historical sync brings over the last 90 days of Mailchimp campaign receives, opens and clicks, once. Anything older stays behind, which is enough to build engaged segments for warm-up.
-
Tags and custom merge fields
Partly / manualThe integration does not sync tags. We filter Mailchimp by tag, export each segment and import it into Klaviyo as profile properties, so nothing you've been collecting is lost.
-
Segments
RebuiltNo import path. Rebuilt in Klaviyo from profile properties, events and predictive fields, which usually means fewer, sharper segments.
-
Automations (Customer Journeys)
RebuiltMailchimp's automation flows don't transfer. Each one is rebuilt as a Klaviyo flow with trigger, filters and splits, and tested before a real customer enters it.
-
Email templates
RebuiltOnly custom-coded Mailchimp templates can be exported as HTML; drag-and-drop templates cannot. We rebuild in Klaviyo using your existing emails as reference, converting merge tags (*|FNAME|* becomes {{ first_name }}).
-
Sign-up forms and pop-ups
RebuiltRebuilt as Klaviyo forms and swapped in on the storefront, so new subscribers land in Klaviyo with the right consent and source.
-
Order and customer history
MigratesComes from your store, not Mailchimp. Klaviyo's Shopify integration syncs the last 90 days first, then your full order history.
-
Sending domain and reputation
Partly / manualYour domain's reputation travels with it, good or bad. The branded sending domain gets new DNS records from Klaviyo, and a new Klaviyo account still ramps volume from your most engaged profiles first, per Klaviyo's warming guidance.
Mailchimp to Klaviyo mapping: what each thing becomes
Mailchimp and Klaviyo use different words for most of the same jobs. This is the translation we work from, and how each item gets across.
| In Mailchimp | In Klaviyo | How it gets there |
|---|---|---|
| Audience | List | Klaviyo's Mailchimp integration creates one Klaviyo list per audience. |
| Contact (subscribed, unsubscribed, non-subscribed) | Profile | The integration syncs name, email address, location and consent status. Klaviyo bills active profiles, so unsubscribed contacts stop costing you. |
| Unsubscribed and cleaned contacts | Suppressed profiles | Added to the Klaviyo suppression list by the integration. Profiles that already existed in Klaviyo need a manual check. |
| Tags | Custom profile properties (or lists) | Not synced. Filter by tag in Mailchimp, export each as a CSV and import it as a property. |
| Groups (interest groups) | Custom profile properties | Not synced. Export each group and import it as a property, so preference-based segments still work. |
| Merge fields and merge tags | Profile properties and Klaviyo template tags | Extra merge fields are exported and imported. In templates, *|FNAME|* becomes {{ first_name }}. |
| Member rating | Profile property | Synced by the integration when "Create Klaviyo lists from Mailchimp audiences" is on. |
| Segments | Segments | No import path. Rebuilt on profile properties, order and browse events and predictive fields. |
| Customer Journeys and automations | Flows | No import path. Each journey is rebuilt as a flow with trigger, filters and splits, then tested on sample profiles. |
| Campaign reports | Engagement history on profiles | The last 90 days of receives, opens and clicks import once. Export older reports before you close Mailchimp. |
| Email templates | Templates | Custom-coded templates export as HTML; drag-and-drop templates are rebuilt using your sent emails as reference. |
| Sign-up forms and pop-ups | Klaviyo sign-up forms | Rebuilt and swapped on the storefront, so new subscribers land in Klaviyo with consent and source. |
| Mailchimp's Shopify connection | Klaviyo's Shopify integration | Order history comes from the store. Disconnect Mailchimp from Shopify before connecting the Mailchimp integration. |
Using Klaviyo's Mailchimp integration for the move
For a migration, Klaviyo's built-in Mailchimp integration is a one-way pipe: it gets your data out of Mailchimp, then you remove it. What it syncs, and how to run it alongside Mailchimp, is in our guide: How the Klaviyo Mailchimp integration works.
What it pulls from Mailchimp
Contacts, audiences as Klaviyo lists, subscription status, unsubscribes, cleaned addresses and member ratings, connected with a Mailchimp API key. It also imports the last 90 days of campaign receives, opens and clicks, once.
What it leaves behind
Tags, custom merge fields, segments, automations, templates and forms, which we export or rebuild. Nothing flows back from Klaviyo to Mailchimp.
Running both during the move
Keep it connected while forms switch, so new Mailchimp sign-ups still reach Klaviyo, but never let both platforms send. Disconnect Mailchimp from Shopify first, or the integration can fire double opt-in emails at your existing list.
/ What breaks in bad migrations
Where DIY Mailchimp migrations go wrong.
These are the things most brands lose when they migrate without a structured process. Each one is fixable, but only if you know to fix it before cutover, not after.
- Double opt-in emails fired at the whole existing list because Mailchimp was still connected to Shopify when the integration went in
- Tags left behind: Klaviyo's Mailchimp sync doesn't carry them, so tag-based segments quietly disappear
- Automations flattened into one-size-fits-all flows because Mailchimp logic was copied, not re-engineered
- Cleaned addresses sneaking back into sends because the profiles already existed in Klaviyo before the sync
- The full list blasted on day one from a new account instead of warming from engaged profiles first
- Sign-up forms still feeding Mailchimp for weeks after cutover, or both platforms sending the same abandoned cart email
How to migrate from Mailchimp to Klaviyo, in 5 steps.
Same process every time. Same outcome every time. Done-for-you, fixed timeline, full transparency.
-
01 PHASE Audit the Mailchimp account
Inventory of your Mailchimp account: audiences, tags, groups, merge fields, segments, Customer Journeys, templates, forms, sending domain and deliverability baseline. Every item gets a verdict: migrate, rebuild or retire.
-
02 PHASE Set up Klaviyo and connect your store
Klaviyo account created and connected to your store first, so order history is syncing while everything else is built. Branded sending domain authenticated with Klaviyo's DNS records. Profile properties mapped from your Mailchimp tags, groups and merge fields.
-
03 PHASE Move contacts, consent and tags
Mailchimp disconnected from Shopify, then Klaviyo's Mailchimp integration connected to pull contacts, consent status, unsubscribes, cleaned addresses and 90 days of engagement. Tags and groups exported and imported as properties. Suppressions checked before anything sends.
-
04 PHASE Rebuild Customer Journeys as flows
Every Mailchimp automation rebuilt as a Klaviyo flow, templates rebuilt with merge tags converted, segments and forms rebuilt. Each flow tested against sample profiles before a real customer can enter it.
-
05 PHASE Cut over and warm up
Forms pointed at Klaviyo, Mailchimp automations paused, Klaviyo flows live, integration removed. First campaigns go to your most engaged profiles, widening as engagement holds. Daily deliverability monitoring for the first 14 days post-cutover.
What a Mailchimp to Klaviyo migration costs, hidden costs included
Three lines: the plan difference, the overlap month and the migration project, then the hidden costs most budgets miss. Monthly list prices in USD, no promotions. Mailchimp Standard from mailchimp.com (10 October 2026); Klaviyo email plan from klaviyo.com (1 October 2026).
| Cost line | 5,000 contacts | 10,000 | 25,000 | 50,000 |
|---|---|---|---|---|
| Mailchimp Standard, a month | $100 | $135 | $310 | $450 |
| Klaviyo email plan, a month | $100 | $150 | $400 | $720 |
| Plan difference, a month | $0 | +$15 | +$90 | +$270 |
| Overlap month (both plans live) | $200 | $285 | $710 | $1,170 |
| Migration project, one-off | $3-15K, depending on scope. The free audit puts your exact price in writing. | |||
- Compare billable counts, not list size. Mailchimp bills subscribed, unsubscribed and non-subscribed contacts. Klaviyo bills active profiles and doesn't count suppressed ones, so a list with a long unsubscribed tail can land a tier lower in Klaviyo. Full tables: Mailchimp pricing and Klaviyo pricing.
- On Mailchimp Essentials instead? It is $75, $110, $270 and $385 a month at the same sizes, but caps automation flows at four steps.
- The overlap month assumes one billing cycle with both platforms live while forms switch and flows go live. Downgrade or close Mailchimp once you have exported the reports you want to keep.
- SMS is extra on both platforms. Klaviyo's US texts start at $15 a month for 1,000 (1 October 2026).
- The hidden costs: the overlap month; importing contacts you will never email, since every active profile counts toward your Klaviyo plan; rebuilding drag-and-drop templates, which Mailchimp can't export; and exporting the campaign reports you want to keep before you close the Mailchimp account.
Mailchimp to Klaviyo migration FAQ
Q.01 How long does a Mailchimp to Klaviyo migration take? +
/ Answer
Two to three weeks for a standard account, four to six weeks for complex accounts with custom integrations. Domain warm-up then continues for several weeks after cutover as sends widen from your most engaged profiles to the rest of the list.
Q.02 How do I migrate from Mailchimp to Klaviyo? +
/ Answer
Five steps: audit what you have in Mailchimp; set up Klaviyo, connect your store and authenticate your sending domain; disconnect Mailchimp from Shopify and use Klaviyo's built-in Mailchimp integration to pull contacts, consent, suppressions and 90 days of engagement (tags need a separate export); rebuild automations, templates, segments and forms; then cut over in order: forms to Klaviyo, Mailchimp automations paused, Klaviyo flows live.
Q.03 Can Klaviyo's Mailchimp integration do the migration for me? +
/ Answer
Only the data part. It syncs contacts, audiences, subscription status, unsubscribes, cleaned addresses and the last 90 days of campaign engagement from Mailchimp into Klaviyo, one way. It doesn't move tags, segments, automations, templates or forms, and Klaviyo recommends removing it once the migration is complete.
Q.04 Can I run Mailchimp and Klaviyo at the same time while moving? +
/ Answer
For a short transition, yes. The integration keeps syncing new Mailchimp sign-ups into Klaviyo while you switch forms. Just never let both platforms run automations or campaigns at the same time: customers get duplicate emails, and unsubscribes in Klaviyo don't sync back to Mailchimp.
Q.05 Will I lose subscribers when moving from Mailchimp to Klaviyo? +
/ Answer
No. Contacts come across with the subscription status they had in Mailchimp, and unsubscribed and cleaned addresses are suppressed in Klaviyo, as they should be. The one gap to check: profiles that already existed in Klaviyo before the sync are not suppressed even if Mailchimp cleaned them.
Q.06 Does my Mailchimp engagement history transfer? +
/ Answer
Partly. The integration imports the last 90 days of campaign receives, opens and clicks, once. Older history stays in Mailchimp, so export any reports you want to keep before closing the account. Ninety days is enough to build the engaged segments that warm-up depends on.
Q.07 What happens to my Mailchimp automations and Customer Journeys? +
/ Answer
They are rebuilt as Klaviyo flows. There is no import path, and a straight copy would waste the switch, so each flow is re-engineered with Klaviyo filters and splits, then tested on sample profiles before it goes live.
Q.08 What happens to my Mailchimp templates? +
/ Answer
Custom-coded Mailchimp templates can be exported as HTML; drag-and-drop templates cannot. Either way we rebuild them in Klaviyo using your current emails as reference and convert merge tags such as *|FNAME|* to {{ first_name }}. It's also the cheapest moment to strip the drag out of your designs.
Q.09 Do I need to warm up my sending domain after switching? +
/ Answer
Your domain's reputation comes with you, but a new Klaviyo account still has to establish itself. Klaviyo's guidance for new customers is to start with recently engaged profiles and widen the window over several weeks while engagement holds. Don't send to the full list on day one.
Q.10 What does a Mailchimp to Klaviyo migration cost? +
/ Answer
The project runs as a fixed-scope Project Engagement: defined deliverables, a timeline agreed upfront and a single fee, typically $3-15K depending on scope. On top of that, budget for the plan difference and about one month of paying for both platforms while you cut over. At 10,000 contacts that overlap month is $285 at list price ($135 for Mailchimp Standard plus $150 for Klaviyo). The free migration audit gives you the exact scope and price in writing within 24 hours.
Q.11 Will Klaviyo cost more than Mailchimp? +
/ Answer
At list price, from about 10,000 contacts up, yes. Mailchimp Standard is $135 a month at 10,000 contacts against Klaviyo's $150, and $450 against $720 at 50,000; at 5,000 both are $100 (Mailchimp checked 10 October 2026, Klaviyo 1 October 2026). But Mailchimp counts unsubscribed and non-subscribed contacts toward your plan, while Klaviyo bills active profiles and skips suppressed ones, so lists with a large unsubscribed tail often close the gap. We model both platforms' cost on your actual list during the audit.
Q.12 Can I migrate from Mailchimp to Klaviyo myself? +
/ Answer
Yes. Klaviyo's integration moves the contacts. The contacts were never the hard part. The flows, the segments, the cutover order and the warm-up are where DIY migrations lose revenue, and that's the part we're paid to engineer.
/ Related guides
GUIDE
Mailchimp Pricing
Every plan and the real cost
GUIDE
Klaviyo vs Mailchimp
Which one fits your store
GUIDE
Klaviyo Pricing
Every tier, SMS rates, add-ons
/ Migrating from a different platform?
Ready to migrate from Mailchimp?
Free migration audit, no commitment. Account audit, flow inventory, subscriber review, timeline. Written plan within 24 hours.
Or browse all migrations →/ Free Audit
Get your free migration audit
Drop your store URL and email. We'll review your email program and send a written 90-day revenue roadmap within 24 hours. No obligation.