Track UTMs via Thank-You Page Webhook

UTM attribution overview

Send full HandL UTM Grabber attribution from Cal.com UTM Tracking Integration bookings to Zapier, Make, or your CRM using a custom confirmation page and webhook.

Primary setup: How to Track UTMs in Cal.com

Custom confirmation redirect

Point your booking tool at a WordPress thank-you page after the appointment is confirmed. Include the customer email in the redirect URL when the tool supports it.

Webhook script on thank-you page

Use the merge script from Triggering Zapier on Thank you Page to combine URL parameters with handl_utm and send the full payload to your webhook.

Verify the payload

Book a test appointment from a page with ?utm_source=booking-test. Check that utm_source, gclid, and email (if passed) arrive in Zapier or Make.