Google Analytics shows you the source of traffic and ideally purchases. Those reports don't always work as expected. In this Analyzify help center article; we will show you how you can fix UNWANTED REFERRALS both on Google Analytics 4 and Universal Analytics.
Google Analytics Referral Problem for Shopify Stores:
The problem: You are seeing unnatural referrals on your Google Analytics reports - and it breaks your reports. They are not the actual referrals - but only another website the user has visited in between the session.
The solution: Using Google Analytics' referral exclusion setting.
The most common unwanted referrals are:
- Payment Providers (PayPal, Stripe, Klarnapayment, etc)
- Your current domains (if you have more than one domain or if you have changed your domain)
- Checkout Processors (Carthook, Recharge, etc)
Find Referrals to Exclude
You need to know the domains that you will add. Follow the path:
Universal Analytics > Left Menu > Acquisition > All Traffic > Referrals
You will see a report like above. You are looking for unnatural referrals here such as: PayPal, Stripe, Myshopify.com, Recharge.com, etc. Note them down and move to the next step.
A Note: Social media referrals shouldn't also be here - especially if you are running ads. However, you DO NOT want to exclude them. They are actual traffic sources. But you want to make a correct UTM set up so that the traffic source is defined correctly such as paid, campaign name, ad name, etc. Check out this article for the best possible UTM setup.
Set up Referral Exclusions on Universal Analytics
We will need to set this up for Universal Analytics (UA) and GA4 separately. Let's start with UA.
Make sure you are in the UA account. Click Admin from left bottom corner and then
Second Column > Tracking info > Referral Exclusion list
You should just add the domains one by one on the next page. Make sure to add your own domains as well. An important note - referral exclusions work the best at the domain level - so don't add subdomains but domains.
Instead of adding yourstore.myshopify.com - you should add myshopify.com. Add all the domains you have found - and then move to the GA4 setup.
Set up Referral Exclusions on Google Analytics 4 (GA4)
We'll do the same setting on different screens. Make sure that you are on your GA4 account.
Left bottom corner Admin > 2nd Column > Data Streams
(if you are not seeing Data streams here, you are most probably not on your GA4 account)
Click on your Data Stream and then choose "More Tagging Settings" just like below 
There is a slight difference between UA and GA4 on this matter. We will need to make two different settings for internal domains and external domains.
List your own domains and myshopify.com on the Configure your domains section.
And Referrals on the List unwanted referrals section.
Done! Please note that Referral Exclusion will start working after you make these changes. Unfortunately it doesn't reflect on the past data.