Set up Klaviyo integration and newsletter opt-in in Regal Forms

Updated September 20, 2026

Klaviyo integration in Regal Forms lets a form send an explicitly opted-in contact to a selected Klaviyo list after its entry has been saved. Contacts are not sent unless they tick the mapped Join Newsletter field.

Set up Klaviyo integration in Regal Forms#

1. In Klaviyo, create or choose the email list that should receive new subscribers. Copy its list ID.
2. Create a Klaviyo private API key with Lists, Profiles and Subscriptions write access.
3. In WordPress, open Regal Forms → Settings, enter the Klaviyo private API key in Newsletter integrations and save it.
4. Edit the form. Add an Email field and add a Join Newsletter field with clear consent wording.
5. Add the dedicated Name field if you want to send first and last names.
6. Open Form settings, enable Klaviyo newsletter, then map the Join Newsletter, Email and optional Name fields.
7. Enter the Klaviyo list ID, select the opt-in method that matches that list and save the form.

Single and double opt-in for Klaviyo#

Klaviyo controls the actual subscription process from the selected list. For single opt-in, select a single-opt-in Klaviyo list so the contact is subscribed immediately. For double opt-in, select a double-opt-in list so Klaviyo sends its confirmation email and the contact remains pending until they confirm.

The opt-in choice in Regal Forms is a configuration check: it should always match the selected Klaviyo list. A successful form entry can still be stored while Klaviyo awaits a double-opt-in confirmation.

Checks if contacts do not appear#

• Confirm the Join Newsletter checkbox was ticked in the entry.
• Check the mapped Email field contains a valid email address.
• Confirm the private API key and Klaviyo list ID are correct.
• For double opt-in, check pending contacts and confirmation emails in Klaviyo before expecting an active subscription.

Klaviyo’s server-side subscription guidance confirms that the selected list determines whether a contact is immediately subscribed or must confirm first. See Klaviyo Subscribe Profiles.