Book Now Book Now

Google Tag Manager: Cross Domain Tracking for Conversion Events

Step 1. Open Your Google Tag

In GTM, go to Tags.

Click your Google Tag (the one that loads your GA4 Measurement ID).

If you don’t already have one, create a new Google Tag and paste in your Measurement ID (G-XXXXXXX).

Step 2. Expand Configuration Settings

Inside the tag, scroll down and open Configuration Settings.
(This replaces “Fields to Set” in the old GA4 Configuration tag.)

Click Add Row.

  1. Parameter Name: linker
  2. Value:
    { "domains": ["yourdomain.com","checkoutdomain.com"] }

This tells GA4 to auto-link those domains by appending the _gl parameter when users click between them.

Step 3. Save & Publish

Save the tag.

Publish your container.

Step 4. Add Referral Exclusions in GA4

Even with cross-domain linking, GA4 may still record “self-referrals” unless you exclude them:

Go to GA4 Admin → Data Streams → Web Stream → Configure Tag Settings → List Unwanted Referrals.

Add:

  • yourdomain.com
  • checkoutdomain.com

Step 5. Test

  1. Enable Preview Mode in GTM.
  2. Click a link from Domain A → Domain B.
  3. The URL should include a ?_gl=... parameter.
  4. Check GA4 Realtime to confirm that it stays one session.

That’s it — in the new GTM, you use Google Tag → Configuration Settings → linker field to achieve cross-domain tracking.




Talk to us about Google SEO Services & Marketing Support

Real Content Advice. Real Results. Real-time Local SEO Services.

This is the perfect starter program to get access to Google Local SEO services for your website and helping you get found on Google.  We work with you and your team to help you and your business grow.

Request a Callback

Get a callback from one of our Local SEO & Google Marketing Experts today.

I want to find out more about...

Callback Time Preference
What would you like to achieve with our help?
Terms & Conditions

Click here to view Terms & Conditions

Get Optimised & Get Found on Google Today

Get discovered on Google. Meet with our Chief Google Business Specialist Katrina Puranik to explore the power of Google and how we can help your business. 

GET STARTED NOW GET STARTED NOW
REQUEST A CALLBACK
REQUEST A CALLBACK

Check out Oncord - Your Wesbite Marketing Platform

Oncord - Website Marketing Platform