Peter

If you use WooCommerce Memberships or Subscriptions and Klaviyo, you will want to use this plugin. It enables you to synch membership status changes to Klaviyo. If you use WooCommerce Subscriptions, it will also synch subscription info and events.
This plugin should probably be used in conjunction with Klaviyo’s official WooCommerce integration since this plugin is only synching status changes from WooCommerce Memberships and Susbcriptions. It does not build full profiles nor synch orders (which the official plugin does just fine).
To use:
<ol>
<li>Go to your Klaviyo.com dashboard and click on your account name (bottom left), then Settings, then API Keys. Then click “Create Private API Key”.</li>
<li>Give the key a name like “WooCommerce Memberships Synch”</li>
<li>Leave the Access Level on “Custom” and select “Read/Write” for Events, Metrics and Profiles. You can leave everything else on “No Access”.</li>
<li>Click “Create”</li>
<li>On the next screen, copy the API Key, then head over to your WP Admin Dashboard and click Settings -> Klaviyo Memberships Sync.</li>
<li>Paste in the API Key and click “Save Changes”.</li>
<li>You can batch synch all your existing members by entering the Membership Plan ID and starting a batch to run in the background.</li>
</ol>
From now on, whenever a Membership status changes, it will be synchronized to Klaviyo. If the Membership is related to a Product, the Product Name will also be synched. In Klaviyo, you will see the current status on a user’s profile properties, and you will see a list of events for every status change.
Subscription status changes, switches, renewal failures and successful payments are also synched.
Note: The API updates are delayed by 5 minutes to avoid multiple status change updates in a short succession (which would happen if you are using WooCommerce Subscriptions since it pauses and reactivates Memberships during the renewal process).
<h4>Current Limitations</h4>
If you use multiple Membership Plans, you’ll only see the one with the most recent change on the user’s Profile in Klaviyo.
This plugin is ideal for stores that have one Membership Plan and allow customers to have only one Subscription.
<h3>External services</h3>
This plugin connects to the Klaviyo API to send data about memberships and subscriptions.
It sends basic identifying information (e.g. name and email address) about users who have memberships and subscriptions, as well as the membership and/or subscription status, name, dates, and other details.
Since you are using your own API Key, data is sent directly from your WordPress install to Klaviyo, and the author of this plugin is completely out of the loop. The plugin uses Action Scheduler to process API requests in the background and reduce risk of hitting rate limits, but you are responsible for your own rate limit.
The API used is provided by Klaviyo using your own key: <a href="https://www.klaviyo.com/legal/api-terms" rel="nofollow ugc">API Terms</a> & <a href="https://www.klaviyo.com/legal" rel="nofollow ugc">General Terms and Privacy Policy</a>.

PG Sync for Klaviyo and Woo Memberships and Subscriptions

This is a very lightweight plugin that synchs WooCommerce Memberships and/or Subscriptions to Klaviyo.

PluginsCafe

Kaisar Ahmmed

The Klaviyo Integration plugin empowers you to easily add or subscribe users to your Klaviyo lists straight from your WordPress forms. With built-in support for multiple top-tier form builders, you can ensure your email marketing campaigns are automatically populated without any manual data entry.
Supported Form Builders: 
* Gravity Forms 
* Contact Form 7 (CF7) 
* WPForms 
* Elementor Forms
Features: 
* Subscribe users to any of your Klaviyo lists upon form submission. 
* Map standard fields (Email, First Name, Last Name) directly to Klaviyo profiles. 
* Simple and intuitive settings directly inside your form builder. 
* Fully integrates with the official Klaviyo Lists API.
Important Notice: 
To use this plugin, you will need a valid Klaviyo API key. By using this plugin and Klaviyo’s services, you agree to Klaviyo’s Legal, Terms, & Policies available here: https://www.klaviyo.com/legal.

Integrate Klaviyo with Contact Form 7, Gravity Forms, WPForms and Elementor Forms

Seamlessly connect your favorite WordPress form builders to Klaviyo and automatically subscribe users to your email and SMS lists.

PG Sync for Klaviyo and Woo Memberships and Subscriptions vs Integrate Klaviyo with Contact Form 7, Gravity Forms, WPForms and Elementor Forms