How to migrate from another email service provider to Klaviyo

You will learn

Learn how to migrate from another email service provider to Klaviyo. If you are moving from an email service provider (ESP) like Mailchimp or Constant Contact, Klaviyo should fully replace any other email platform you might use. While we do offer integrations with other ESPs, these are meant for one-time use to migrate your contacts into your new Klaviyo account.

Before you begin

If you see your ESP listed below, follow its migration guide. Depending on the provider, you can use a built-in integration or export your data and import it into Klaviyo:

• Mailchimp
• Constant Contact
• Campaign Monitor
• HubSpot
• Listrak
• Sailthru
• Salesforce Marketing Cloud

Some ESPs provide their own guidance on how to migrate to Klaviyo.

Before importing contacts, clean your lists and identify your engaged subscribers using the guidance in Important considerations and best practices. CSV imports can trigger list-based flows, including your welcome series. If you already have a live welcome series, follow the welcome series import guidance before uploading contacts to avoid sending welcome messages to existing subscribers.

Key guidelines

1. Swap out embedded simple sign-up forms
   Make sure to switch all existing sign-up forms on your site to Klaviyo forms to ensure these individuals now get added to your email list in Klaviyo.
2. Redirect integrated subscriber forms
   If you're using any third-party form tools (e.g. Wufoo, forms on Facebook, etc.) to send people to your ESP, make sure to adjust these so they point to Klaviyo.
3. Sync subscribers at checkout
   If you're automatically collecting email subscribers through your shopping cart checkout process, make sure these subscribers get synced to Klaviyo; for platforms like Shopify and Magento, this feature is available via the standard integration.
4. Migrate saved email templates
   If you are interested in transferring existing email templates from your former ESP to Klaviyo, you can follow our guide on importing a custom HTML template.
5. Ensure all existing subscribers are added to Klaviyo:
   1. If you're using Mailchimp, Campaign Monitor, or Mad Mimi, Klaviyo has built-in integrations to sync existing lists, which you can find by:
      
      1. Selecting the Integrations tab in Klaviyo.
      2. Clicking Explore apps.
      3. Searching for your ESP, selecting it, then clicking Install and following the process.
   2. If you're using an ESP that we don't integrate with, such as Constant Contact, or already have a subscriber list in a file, you can import your subscribers to Klaviyo. If your list is saved as an Excel workbook, save it as a CSV file before uploading.
6. Import current hard bounces and unsubscribes
   Check which suppressions your ESP integration transfers before sending. For example, Campaign Monitor syncs unsubscribes but does not import its bounced subscriber list. Upload any hard-bounced addresses and unsubscribes that have not synced to your suppression list in Klaviyo.
7. Migrate current autoresponders
   After importing your contacts and checking your suppressions, recreate your existing autoresponders as Klaviyo flows. Test the flows before setting them live, then turn off the corresponding automations in your former ESP to avoid duplicate messages.

Before closing your previous ESP account, verify that your contacts and suppressions have migrated and test your sign-up forms and flows. Once these checks are complete, you can discontinue sending email from your previous ESP.

Important considerations and best practices

1. Make sure you have imported the data you need from your previous ESP into Klaviyo. Check your provider’s migration guide for what transfers, and save exports of any other data or reports you want to keep before closing your previous account.
2. After switching all your sign-up forms to point to Klaviyo, wait a few days and watch your lists in your former ESP. If you notice subscribers are still being added to these lists, there's probably at least one form that still needs to be swapped out.
3. Another important thing to consider before importing any existing email lists is list cleaning. We highly recommend that you import clean lists into Klaviyo and send to an engaged list from your first send - if you intend to sync over existing email lists, or manually import existing lists into Klaviyo, your email deliverability may be at risk if you skip this step.
4. Your former ESP most likely provides a way to analyze the engagement level of your main list, using data points such as open rates, bounce rates, etc. Before you migrate any existing subscriber lists into Klaviyo, we recommend using all data available to isolate and remove any invalid or inactive emails that will only bloat your sending and drag down your deliverability. This should all be done in advance of your first send with Klaviyo. If Klaviyo doesn't provide a built-in integration with your ESP, there are two ways you can make sure you're sending to an engaged list:
   1. Upload a main list with engagement data as custom properties.
   2. Upload separate main, engaged, and inactive lists.

After either option, you should send exclusively to your engaged list or segment for your first few campaigns. If you send daily, send to this group for the first week. If you send more than once a week, send your first 2-3 campaigns to this list or segment.

Outcome

You've now migrated from another email service provider to Klaviyo.

Additional resources