Tracking HubSpot forms

Before you begin

•This solution is built for HubSpot Forms v4. If you're on an older forms version, upgrade your forms to v4 first.
•It works only on embeddedHubSpot forms, not HubSpot-hosted forms. FunnelTrack can't deploy its pixel on HubSpot-hosted pages, so those submissions can't be tied to a web session.
•Make sure the FunnelTrack pixel is loaded on every page of your site, including the pages that host your forms.

HubSpot form share panel showing the embed code — Use HubSpot's embedded form (the embed code), not a HubSpot-hosted form page.

Complete the shared setup first

This flow assumes you've done the one-time setup on the HubSpot overview: connect HubSpot for your webhook URL, deploy the FunnelTrack pixel, and create the ft_sid and ft_uid contact properties.

Add ft_sid and ft_uid fields to your form

Edit your HubSpot form and add two fields backed by the ft_sid and ft_uid contact properties. These must be the properties you created in the shared setup. For each field:

•Pick a Single-line text field type.
•Set the Label to ft_sid on one, ft_uid on the other.
•Toggle Hidden field on for both.

Choosing the single-line text field type in HubSpot — Field type: Single-line text.

Setting the field label to ft_sid — Label: ft_sid.

Setting the field label to ft_uid — Label: ft_uid.

HubSpot form field editor with the Hidden field toggle enabled — Toggle Hidden field on so buyers never see it.

The HubSpot form showing the hidden ft_uid and ft_sid fields added — Both hidden fields added to the form.

Publish the form

Changes don't take effect until you publish your form updates. Save and publish before testing.

Deploy the injector script on the form page

Add the injector script below to every page that hosts a form, after the FunnelTrack pixel. Order matters: the pixel must load first so it has minted the session before the injector reads it. The script listens for HubSpot's form-ready event and writes the visitor's ft_sid and ft_uid into the hidden fields.

Why capture ft_sid and ft_uid?

ft_sid is the visitor's session id: it stitches the submission to the exact browsing session, so the conversion carries that session's click IDs, UTMs, geo, and device. That powers web attribution today. ft_uid is the durable visitor id: it's the fallback when the session can't be matched, and it's what later ties this contact to offline events (lifecycle and deal changes) back to the ad that acquired them.

<script>
window.addEventListener('hs-form-event:on-ready', function (event) {
  var form = HubSpotFormsV4.getFormFromEvent(event);
  var sidSet = false, uidSet = false;

  function trySet() {
    var ft = window.ft || window.tracker;
    if (!ft) return;
    if (!sidSet && typeof ft.getSessionId === 'function') {
      var sid = ft.getSessionId();
      if (sid) { form.setFieldValue('0-1/ft_sid', sid); sidSet = true; }
    }
    if (!uidSet && typeof ft.getUserId === 'function') {
      var uid = ft.getUserId();
      if (uid) { form.setFieldValue('0-1/ft_uid', uid); uidSet = true; }
    }
  }

  trySet();
  if (sidSet && uidSet) return;

  var start = Date.now();
  var poll = setInterval(function () {
    trySet();
    if ((sidSet && uidSet) || Date.now() - start > 8000) clearInterval(poll);
  }, 100);
});
</script>

The FunnelTrack pixel followed by the ft_sid / ft_uid injector script on the form page's HTML — The injector script deployed on the form page, right after the FunnelTrack pixel.

Build the form-submission workflow

In Automation → Workflows, create a workflow that enrolls contacts on form submission.

Selecting the form submission workflow trigger — Trigger: form submission.

Then choose which form(s) this workflow should track.

Selecting which HubSpot forms to track — Choose the forms to track.

Add the Send a webhook action

Add a Send a webhook action and set the method to POST.

Adding the Send a webhook workflow action — Action: Send a webhook (POST).

Paste your FunnelTrack HubSpot webhook URL as the endpoint.

Pasting the FunnelTrack webhook URL into the HubSpot action — Paste your FunnelTrack webhook URL.

Customize the request body

Choose Customize request body and map the contact properties below. More identity fields mean better advanced matching (higher Event Match Quality) at your destinations.

Use HubSpot's property names as the field keys

The body field key (left column) must be the internal property name HubSpot assigns, not a custom label. For example email, firstname, hs_form_id. FunnelTrack matches on these exact keys.

Field	Required?	Why it matters
`event` (static)	Required	Routes the receiver branch. Set the value to `form_submission`
`ft_sid`	Required	Hard-stitches the submission to the visitor's web session (click IDs, UTMs, geo). Powers web attribution.
`ft_uid`	Required	Durable visitor id. Fallback session match, and the bridge for offline (lifecycle / deal) attribution later.
`email`	Required	Identifies or creates the contact. Hashed for advanced matching at every destination.
`phone`	Recommended	Hashed for advanced matching and as a fallback identifier.
`firstname`	Recommended	Hashed user data — raises Event Match Quality.
`lastname`	Recommended	Hashed user data — raises Event Match Quality.
`hs_form_id`	Optional	Lets you route a specific form differently with a custom event card.
`hs_url_domain / hs_url_path`	Optional	Page context for reporting and debugging.

HubSpot Send a webhook request body mapping with event set to form_submission — Map the properties and add the static value event = form_submission.

Resulting payload

{
  "email": "person@example.com",
  "event": "form_submission",
  "ft_sid": "8cf3a3c2-0689-4160-a310-93c6c34da78e",
  "ft_uid": "d8d1d541-1794-44b5-95d3-dbf0a39a20f1",
  "firstname": "Alex",
  "lastname": "Nguyen",
  "phone": "+15551234567",
  "hs_form_id": "7f3a91c2-4b8e-4d1a-9c6f-2e5b8a0d7c31",
  "hs_url_domain": "example.com",
  "hs_url_path": "/pricing"
}

Enable form tracking in FunnelTrack

In FunnelTrack, open a destination (e.g. Meta CAPI) and enable the All Form Submissions event, mapping it to the destination event you want. You can also create per-form events with the Add More Events option to route a specific form to a different destination event.

Enabling form tracking on a FunnelTrack destination — Enable All Form Submissions, or add a custom per-form event.

Verify

Submit the form, then open the Event Delivery Log. You should see an inbound Form Submission (received) and matching outbound deliveries to each destination. Expand the inbound row to confirm ft_sid and ft_uid are present.

FunnelTrack Event Delivery Log showing an inbound form submission with ft_sid and ft_uid and outbound deliveries — Inbound form submission with ft_sid / ft_uid, delivered out to Meta, GA4, and Google Ads.

Missing ft_sid & ft_uid?

The submission still creates a contact from the email / phone, but the conversion goes out with no click IDs and no session attribution (the Event Delivery Log flags these with an amber warning). Re-check your FunnelTrack pixel deployment, the injector script placement (after the pixel, on the form page), and that the hidden fields are mapped in the webhook body.

How form attribution resolves

ft_sid → direct session lookup (best).
ft_uid → visitor bridge (fallback).
Email / phone → contact upsert (always).