Integrating OptiMonk Campaigns with Klaviyo

This article will walk you through integrating Klaviyo with your OptiMonk campaigns. Once you have completed the steps outlined in this guide, your subscribers will automatically be transferred to your Klaviyo mailing list when they fill out an OptiMonk popup form. This may come in handy if you run marketing campaigns on a regular basis, so subscribers who signed up via OptiMonk will also get notifications about your upcoming promotions and news.

In this article:  


Set up the integration in OptiMonk campaign settings

Here's a short video about the integration setup process if you'd rather watch a video. For a detailed, step-by-step guide, please keep reading.

To set up the integration between OptiMonk and Klaviyo, please follow these steps:

1. First, please log in to your OptiMonk account at

2. Select Campaigns on the left menu, then select the Campaign you wish to connect with Klaviyo:


3. Click on Edit settings on the right-hand side:



4. If you've used Klaviyo integration before or if you have Klaviyo added to your site, OptiMonk will recommend adding a Klaviyo integration to your campaign. Here, click on Select:



Or you can always Select Klaviyo from the list of available integrations:


5. You will see the following window where you'll be asked to provide the public and private API keys of your Klaviyo account:



6. To insert the API key from your Klaviyo account, please log in to your Klaviyo account in a new browser window, and click on your username in the bottom left corner and choose Settings to continue. Here select API Keys under the Settings tab. Your public API key will be shown to you right away that you can simply copy and paste to the right field of the OptiMonk integration wizard.



7. If you haven’t created your own private API key yet, click on Create Private API key to generate a new one. Be sure to create a Full Access API Key.

8. To copy the API Key, click on the small icon to copy the key and copy and paste it into the right field of the Optimonk integration wizard.

9. Give the integration a name in OptiMonk, then click Next to continue.

10. Next, you'll be asked to select a Klaviyo list that you would like to link your campaign with. Simply click on the list from the dropdown that you would like the data to be sent to from your OptiMonk campaign.


11. To finish the integration settings, OptiMonk gives you an option to select and check Field mapping.

Here you can find all data from your OptiMonk campaign that you can transfer to your Klaviyo account. For every input field on your OptiMonk campaign, you can assign a field in your Klaviyo list. Once you have linked the corresponding fields, the data from your OptiMonk campaign will be transferred to the right place in your Klaviyo list.


The default field identifiers in Klaviyo are as follows:



The visitor's unique identifier


Email address


First name


Last name


Phone number


Your position within the company


Organization name












Ticking the Checkbox

address 1

First line of address, usually street number and name

address 2

Second line of address, usually apartment number

You can send additional data into Klaviyo by adding custom campaign tags.

2) Examples

Let’s see how to associate the fields with some practical examples as well:

1) OptiMonk campaign collecting basic subscriber data, such as first name and email address:

Sample popup with email and first name input elements:

Input field bindings: with these settings, only the first name and the email of your visitors that you’ve collected on the popup form will be transferred to your Klaviyo list:


After subscribing, you will see your leads' data in OptiMonk as:

The contact information in the Klaviyo list will contain the following data:

2) OptiMonk campaign collecting basic subscriber data with coupon code

Sample popup with a first name input field element, an email input field element, and a coupon code element:

Input field bindings: By applying these settings, the first name, the email address, and the displayed coupon code will be transferred to your Klaviyo list:


After subscribing, you will see your leads' data in OptiMonk as:

The contact information in the Klaviyo list will contain the following data:


This ‘OptiMonk campaign coupon code’ (which you can name as you wish) data will automatically appear at your Email templates - custom properties in Klaviyo. If you insert this property into your form you will be able to set up your email flow using the coupon codes displayed to your OptiMonk subscribers.


3) OptiMonk campaign with basic subscriber data, custom fields, and a static field

Sample popup with email and custom fields, plus a static field:


Input field bindings: In this case, the email address, the custom field data (Favorite color), and also a static field (OptiMonk Summer Campaign) will be transferred to the Klaviyo list:



After subscribing, you will see your leads' data in OptiMonk as:

The contact information in the Klaviyo list will contain the following data:


13. Once you are done with the field binding, click Done and Next in the top right corner to finish the setup.

That's it! :) Whenever a visitor signs up through your OptiMonk popup, they will automatically be added to the Klaviyo list you have selected.


Double Opt-in


I also would like to announce that the double-opt-in is now a switchable option in Klaviyo integration.

A subscriber will only be validated and added to your Klaviyo subscriber list in case they accept the follow-up confirmation email.

If the double opt-in option is not something that is legally necessary for your country, you can turn off the option as far as we know. Klaviyo offers a guide for this option, which you can access at the following link:

Campaign with phone numbers, compliance & consent management

To collect phone numbers into Klaviyo, you can run either

  • campaigns with multiple different input fields as seen above (first name, email, phone number)
  • or phone number-only campaigns. Either way, OptiMonk supports phone numbers and consent collection, forwarding it to Klaviyo where phone numbers will be merged with the right profile.

How collecting consent in Klaviyo works

💡 Klaviyo allows SMS communication only for contacts who have expressed their consent previously. You can see whether a phone number has consented on the contacts profile. Phone numbers and emails belonging to a profile will have to consent separately. Learn more about how consent is handled in Klaviyo.


Phone numbers collected via popups are now forwarded to Klaviyo along with consent in all supported regions, thus, SMS communication can be sent to new list members right away in the United States and Canada.

In the UK and Australia, merchants must have an alphanumerical sender ID before sending SMS messages, which can be done in their Klaviyo accounts by switching on the SMS plan.


💡 Strict consent laws require merchants to include how SMS consent is handled in terms of service and privacy policy, both of which must be displayed on the popup when customers give their email addresses.
Your terms of service can be hosted by Klaviyo. Read more about how.

💡 Find popup templates with a pre-written consent disclaimer here.

If you have any further questions or need any help, please contact us at, and we will be happy to assist you :)


Have more questions? Submit a request