Migrate the contacts that you have collected in Mailchimp to Omnisend with ease as there's no need to export them first and import from a file later. Built-in integration enables you to skip the selection of attributes step, select the import paraments, and get continuous sync of contacts.


Before you start
Setup process
Contacts engagement
Next steps

You can watch this video or continue to the detailed steps below.

Before you start

You can import the following fields from your Mailchimp contacts lists to Omnisend:

  • Default fields (First name, Last name, Phone, Address line 1, City, State, Zip code, Country code). During the import, these fields will be mapped with the default fields in your Omnisend subscriber profile.

  • We will also transfer your contacts' statuses for the Email channel: Subscribed, Non-subscribed, and Unsubscribed. If that contact was synced from your store to Omnisend with subscribed status but was unsubscribed in Mailchimp, the sync from Mailchimp will update the status. Contact subscription statuses are synced from Mailchimp to Omnisend in real-time. New subscribed contacts are imported from MC to Omnisend in real-time as well.

  • Engagement data (average open rate, and average click rate). These fields will be added to the contacts profile as a custom property with a prefix mailchimp_[stats_name]. Average open and click rates are showing the percentage of campaigns being opened or clicked.

  • VIP and all other tags - will be imported as a contact tag.

  • Language property. It will be imported as a custom property, and it will be named "language" (without "mailchimp_" prefix).

  • Segments - we will add a tag mc_segment_segment_name to every contact for every segment it consists in. So you can easily recreate Mailchimp segments using tag filter in Omnisend.

Any other contact data additional to default properties and tags will be imported as Custom properties to Omnisend.


Since the Birthday date (MM/DD) has a different format than the one from Omnisend (YYYY-MM-DD), it is imported as a custom property. If you want this information to be used for the Birthday automation, you need to change the format of the date in the file and upload it manually. We suggest adding any year for the date field, as it won't influence the automation performance.

Note, the default date-added field will be set to the date when this contact was added to Omnisend. The date when your contact was added to MailChimp will be transferred as a custom property.

Setup process

To enable the integration with Mailchimp, click on the profile icon at the top right corner -> Connected apps -> click on the Connect new app button. On the next page, you need to locate Mailchimp and choose to Connect.

On the next page, you will need to enter the API key generated in your Mailchimp account. To find your API key, you should:

  1. Sign in to your Mailchimp account

  2. Go to the API Keys section of your Mailchimp account or click this link: Your API Keys.

  3. Copy an existing API key or click the Create A Key button.

You may also find the step-by-step instruction on the API key generation.

In the sync settings stage, you can choose what data you want to be synced to Omnisend. Once selected, this data will be synced and updated regularly; however, you can change the settings later.

Here, you can choose:

  • the audience or audiences that you want to sync;

  • tags that should be passed to Omnisend;

  • tag contacts with source: mailchimp tag;

  • trigger the automation for the contacts added to the Segment.

If you choose to sync the data from a particular Audience only, the engagement data will be synced from the selected Audience only. If you move the contact to a different Audience and keep sending emails to that contact, the engagement data won't update.

Once you set the initial settings, you will see the confirmation page.

When the integration is complete, you will be able to check its status, the last sync date, and will be able to change its settings. For example, you may enable Segment entry/exit automation to be triggered.

Once you complete the integration with Mailchimp, all of your contacts and their data will be imported immediately. After that, we will be syncing subscription status and new subscribers from Mailchimp to Omnisend in real-time. All other contact properties (tags, names, etc.) are synced every 24 hours.

Note! If you're going to archive, remove contacts permanently in Mailchimp or even delete your Mailchimp account, contacts will be unsubscribed in Omnisend. Disable sync in Omnisend to avoid this.

Contacts engagement

When you are migrating from one Email service provider (ESP) to another, you need to warm up your sending reputation. Start by sending your emails to the most active contacts and increase their number gradually. To help you estimate your contacts activity, Omnisend is syncing two properties — average open rate, and click rates.

Next Steps

  • Start working on building an outstanding sender's reputation with Omnisend by following our recommendations regarding the content and following the warm-up plan.

  • Overtake our idea of contacting your customers through the communication channel they prefer.

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