Does this work with the free MC4WP plugin or only MC4WP Premium?

Both. SourceLoop attaches attribution to the visitor's session and captures the form submission regardless of whether you're on free or premium MC4WP.

My MC4WP form is shown via a shortcode in a page or post. Is that tracked?

Yes. SourceLoop captures submissions from MC4WP forms inserted via shortcode, Gutenberg block, or widget. Whatever placement method you use, the submission is picked up as long as the host page has the tracking script.

What happens to my MC4WP confirmation message or redirect?

Nothing changes. SourceLoop runs separately and doesn't interfere with MC4WP's success message, redirect URL, or list subscription logic.

I have multiple MC4WP forms on the same page. Are all of them tracked?

Yes. Each form's submission is captured separately as its own conversion. The email submitted dictates which contact in SourceLoop the conversion is attached to.

Does the visitor's data also flow into Mailchimp?

Yes, exactly as it normally does. MC4WP's existing Mailchimp sync is untouched. SourceLoop adds attribution data on its side without changing what reaches Mailchimp.

Web form tracking

How to track lead source in Mailchimp for WordPress

See exactly which channel, content, or campaign drives every signup through your Mailchimp for WordPress (MC4WP) forms.

Updated May 28, 2026 2 min read

On this page

What SourceLoop captures from MC4WP
Before you start
Step 1: Install the SourceLoop tracking script
Step 2: Confirm the MC4WP form is on a tracked page
Step 3: Verify it’s working
Where to see MC4WP signups in SourceLoop
Contacts Hub
Attribution dashboard
Funnel reports

Mailchimp for WordPress is the plugin most WordPress sites use to grow their Mailchimp list, lightweight, well-supported, and free. Where it leaves you hanging is the same place every form tool does: you see signups, but not where the signups came from. This guide brings the marketing channel context to every MC4WP submission.

Three steps, about five minutes.

What SourceLoop captures from MC4WP

Each MC4WP signup arrives in SourceLoop with:

Acquisition channel plus the full UTM parameter set
Page sequence visited before the signup
Time on site before subscribing
Number of visits before they converted
Email and name from the MC4WP form
Original landing page and the URL that referred them
Last-touch source before the signup
Device, country, and browser

Before you start

You’ll need:

A SourceLoop workspace (free trial)
Admin access to your WordPress site
The Mailchimp for WordPress (MC4WP) plugin installed with at least one form configured

Step 1: Install the SourceLoop tracking script

SourceLoop Setup page with the tracking code snippet ready to copy

Add it to your WordPress site’s <head>. Easiest options:

A header-injection plugin (e.g. “Insert Headers and Footers”)
Your theme’s header.php template
A Google Tag Manager Custom HTML tag

Make sure the script loads on every page where an MC4WP form lives.

Step 2: Confirm the MC4WP form is on a tracked page

No per-form configuration is needed. Once the tracking script is live site-wide, every MC4WP form is ready to be tracked. Verify that:

The form is embedded on a published page via shortcode, Gutenberg block, or widget
The form collects an email field (MC4WP requires this by default)
Your caching plugin isn’t deferring SourceLoop’s snippet in a way that prevents it from loading before the form

Step 3: Verify it’s working

Open your MC4WP form’s page in an incognito tab, add ?utm_source=test&utm_medium=verify&utm_campaign=mc4wp-check to the URL, and complete a test signup.

Within seconds, the new contact should appear on the Contacts Hub in SourceLoop with the test UTMs attached.

Where to see MC4WP signups in SourceLoop

Contacts Hub

Each MC4WP signup is a row at app.sourceloop.ai/contacts. Expand for the full pre-signup journey.

Attribution dashboard

app.sourceloop.ai/dashboards/traffic groups your signups by source, medium, and campaign. Helpful for understanding which content actually grows your list.

Funnel reports

Build a funnel in app.sourceloop.ai/funnels ending in “Mailchimp for WP signup”. Slice by source to find what drives newsletter subscriptions vs. what drives traffic that doesn’t convert.

For teams running paid acquisition aimed at list growth, forward MC4WP signups to Google Ads, Meta, and LinkedIn as offline conversions so the bidding algorithms can optimize against real list adds. Connect your Google Ads account covers the setup.

Frequently asked questions

Does this work with the free MC4WP plugin or only MC4WP Premium?

Both. SourceLoop attaches attribution to the visitor's session and captures the form submission regardless of whether you're on free or premium MC4WP.
My MC4WP form is shown via a shortcode in a page or post. Is that tracked?

Yes. SourceLoop captures submissions from MC4WP forms inserted via shortcode, Gutenberg block, or widget. Whatever placement method you use, the submission is picked up as long as the host page has the tracking script.
What happens to my MC4WP confirmation message or redirect?

Nothing changes. SourceLoop runs separately and doesn't interfere with MC4WP's success message, redirect URL, or list subscription logic.
I have multiple MC4WP forms on the same page. Are all of them tracked?

Yes. Each form's submission is captured separately as its own conversion. The email submitted dictates which contact in SourceLoop the conversion is attached to.
Does the visitor's data also flow into Mailchimp?

Yes, exactly as it normally does. MC4WP's existing Mailchimp sync is untouched. SourceLoop adds attribution data on its side without changing what reaches Mailchimp.