SourceTag

Form Setup

Set up SourceTag with Unbounce

Unbounce’s landing page builder includes a form builder with a dedicated hidden field type. You add one hidden field per SourceTag data point and set the field name to match.

What you need

  • SourceTag installed on your Unbounce landing page (added via Unbounce’s Scripts settings)
  • An Unbounce landing page with a form

Step 1: Add SourceTag to your Unbounce page

Before setting up the form fields, make sure SourceTag is loading on the page:

  1. In the Unbounce page builder, go to Scripts (in the bottom left, or via the page settings)
  2. Click Add New Script
  3. Choose Head as the placement
  4. Paste your SourceTag script tag
  5. Save

[IMAGE: Screenshot of Unbounce Scripts settings with SourceTag script added]

Step 2: Open the form in the Unbounce builder

  1. In the Unbounce page builder, click on your form to select it
  2. Double-click to open the form editor (or click the edit icon)

[IMAGE: Screenshot of Unbounce page builder with form selected]

Step 3: Add hidden fields

  1. In the form editor, click Add Field
  2. Change the field type to Hidden
  3. Set the Field Name (or Field Label) to the SourceTag field name (e.g. st_fc_channel)
  4. Leave the default value empty
  5. Repeat for each field

[IMAGE: Screenshot of Unbounce form editor showing hidden field type selection]

Core fields (add these)

  • st_fc_channel
  • st_fc_detail_1
  • st_fc_detail_2
  • st_fc_detail_3
  • st_fc_detail_4
  • st_lc_channel
  • st_lc_detail_1
  • st_lc_detail_2
  • st_lc_detail_3
  • st_lc_detail_4
  • st_fc_landing_page
  • st_lc_landing_page

Optional extended fields

If you have enabled extended field groups in your SourceTag dashboard, also add:

  • st_fc_click_id and st_lc_click_id (click IDs)
  • st_visits (visit count)
  • st_days_to_convert (days since first visit)
  • st_device (device type)

[IMAGE: Screenshot of Unbounce form editor with all hidden fields added]

Step 4: Check field names

For each hidden field, verify that the field name matches the SourceTag field name exactly. In Unbounce, the field name is what gets submitted with the form data.

Click on each hidden field and check the Name or Field Name setting in the properties panel.

[IMAGE: Screenshot of Unbounce hidden field properties showing the field name]

Step 5: Publish and test

Publish (or republish) your Unbounce page. Visit it with UTM parameters:

?utm_source=test&utm_medium=cpc&utm_campaign=unbounce-test

Submit the form. Check the lead in Unbounce’s Leads section. The hidden field values should appear in the lead details.

[IMAGE: Screenshot of Unbounce lead details showing populated hidden fields]

Tips

  • You can copy field names from the Fields page in your SourceTag dashboard (each name has a copy button).
  • Unbounce form submissions include hidden field values in all downstream integrations (webhook, Zapier, email, CRM).
  • If you have multiple forms on the same Unbounce page, add the hidden fields to each form.
  • Unbounce also supports its own UTM parameter passthrough. SourceTag’s hidden fields capture the full attribution picture (first-click, last-click, landing pages, etc.) which goes beyond basic UTM passthrough.