How to Track HubSpot Lead Sources with Hidden UTM Fields

For B2B marketing managers, a lead's name and email aren't enough. You need to know which campaign drove that lead directly in your HubSpot contact record. The secret? Hidden form fields.

HubSpot is incredibly powerful at tracking sources, but passing UTM parameters directly into custom properties gives you much more control over your B2B attribution reporting.

Why Hidden UTM Fields Matter

While HubSpot's "Original Source" property is helpful, it's often too broad for advanced reporting. By capturing utm_source, utm_medium, and utm_campaign directly into contact properties, you can build custom reports that show precisely which LinkedIn ad audience is converting at the highest rate.

Step 1: Create Custom Properties in HubSpot

Before you edit your forms, you need a place for the data to go. Create three new contact properties in HubSpot:

• UTM Source (Single-line text)
• UTM Medium (Single-line text)
• UTM Campaign (Single-line text)

Step 2: Add Hidden Fields to Your Forms

Open your HubSpot Form, add these three new properties, and set their "Field type" to Hidden. This ensures your leads don't see them, but HubSpot is ready to receive the values from the URL.

Step 3: Drive Traffic with Tagged Links

Now, when you build your links in our UTM Builder, ensure the parameter names match what HubSpot expects. When a user lands on your page with those UTMs in the URL, HubSpot's tracking script automatically pulls those values and injects them into the hidden fields when the form is submitted.

The B2B Advantage

Imagine being able to go to your sales team and say, "These 10 leads all came from our 'State of the Industry' whitepaper campaign on LinkedIn." That is the level of clarity provided by properly tagged forms.

This setup is especially critical for LinkedIn Ads, where cost-per-lead is high and every data point matters for optimizing your budget.

Troubleshooting Form Tracking

If your hidden fields are staying blank, check for "Redirects." If your ad link goes to a landing page that then redirects to another page, the UTMs might be getting lost. Check our UTM troubleshooting guide for tips on preserving data through redirects.