Hi @Mel,

Thanks for sharing this information with the Klaviyo community.

If you are using Klaviyo’s legacy signup form code, we have documentation (with code) on adding a “thank you” (what we call a success message) for each type of form. You will find the guides for each type of form below:

Legacy Embed form

Legacy Popup form

Legacy Flyout Form

I’d recommend following one of these guides to create and customize the form because we provide the form code in addition to the code for the “thank you” message (success message) for each. If you are using a completely custom form (non-Klaviyo legacy code), we do not have documentation to help with populating the success message, however, you can feel free to leverage any of the code provided in the aforementioned documentation if that helps you achieve your goal with your custom form.

Also keep in mind, because legacy forms use custom HTML and CSS, our support team is unable to assist with troubleshooting legacy forms. For that reason, we also encourage you to learn more about Klaviyo's standard Signup Form Builder. Here, you’ll find specific information on creating a standard Klaviyo sign-up form. You’ll find more information on the success messages for Klaviyo’s standard forms here.

Thanks for being a member of the community.