HubSpot's own tracking vs Google Ads
HubSpot has built-in analytics and can track form submissions on its own. But HubSpot's tracking and Google Ads' tracking are separate systems with separate attribution models. Getting HubSpot to push conversion data back to Google Ads requires either the HubSpot-Google Ads integration (which requires Marketing Hub Professional at $800+/month) or a manual offline conversion upload workflow.
For businesses using HubSpot's free CRM with embedded forms, there's no native path to Google Ads conversion data.
The GTM approach
HubSpot forms are JavaScript-rendered, not native HTML forms. GTM's built-in form submission trigger doesn't fire. You need to listen for HubSpot's custom JavaScript events, configure a custom trigger, and fire your Google Ads tag on the HubSpot form callback.
This works for technical teams. For a business owner who chose HubSpot because it was supposed to be simple, it's another tool to debug.
How it works with HubSpot Forms
The Tagless script on your page auto-injects a hidden reference field into your form. When someone submits, that reference travels with the form data. Tagless matches it to the GCLID captured when the visitor arrived from Google Ads.
The only setup step: connect via a webhook.
Create a one-step Make.com scenario: trigger on HubSpot form submission, add an HTTP module that calls your Tagless webhook URL. This avoids needing HubSpot's Workflows feature (which requires a paid plan).
When the submission fires, Tagless receives the data, matches the reference to the GCLID, and the lead appears in your dashboard with full attribution — campaign, ad group, keyword.
For a full explanation of the tracking mechanism, see How Tagless Works.
The simpler path
Tagless detects HubSpot form interactions on your page. GCLID captured, submission logged, lead qualified, conversion synced to Google Ads. No HubSpot Marketing Hub upgrade. No GTM custom event configuration.
If you're also getting leads through WhatsApp, email, or phone — channels HubSpot's form tracking can't see — Tagless covers those too in the same dashboard.