If you're running a Shopify store and your GA4 acquisition reports show Stripe, PayPal, or Shopify Payments as traffic sources — especially for sessions that include purchases — your attribution data is broken. This is one of the most common and most damaging configuration gaps in Shopify + GA4 setups, and the fix is a single setting change.

What Is Actually Happening

When a customer clicks "Pay Now" on your Shopify checkout, they're redirected to a payment processor's hosted page (Stripe, PayPal, Klarna, etc.) and then back to your thank-you page. GA4 sees the return from the payment processor as a new session — and attributes it to stripe.com / referral or paypal.com / referral. The original traffic source — your Google Ads campaign, your email newsletter, your organic search ranking — is permanently overwritten.

The result: purchases appear to come from payment processors, your real acquisition channels look underperforming, and ROAS calculations are meaningless.

The Shopify-Specific Domain List

Shopify's checkout flow involves more domains than a standard e-commerce setup. Your referral exclusion list needs to cover all of them:

→stripe.com
→checkout.stripe.com
→paypal.com
→pay.google.com
→klarna.com
→afterpay.com
→shop.app (Shopify's Shop Pay)
→shopify.com (if your checkout is on a Shopify subdomain)

Add any other payment processors your store uses. If you're unsure what's hitting your referral report, go to Reports → Acquisition → Traffic Acquisition, change the primary dimension to Session source/medium, and filter for / referral — any domain appearing there that isn't a legitimate referring site should be excluded.

How to Add Referral Exclusions in GA4

  1. Go to Admin → Data Streams → select your web stream
  2. Click Configure Tag Settings
  3. Click Show All and select List Unwanted Referrals
  4. Add each domain from the list above
  5. Click Save

The fix applies to all future sessions. Historical data where attribution was overwritten cannot be corrected.

This also applies to Shopify Markets and international checkouts. If your store uses region-specific payment processors for different markets, ensure those domains are also excluded. A single missing exclusion can corrupt attribution for an entire geography.

Verify Your Exclusions Are Complete

GA4 Health Check's Configuration & Customization module checks your referral exclusion list as part of the automated audit — flagging any payment processor domains that are missing. See the full list of configuration checks in our comprehensive GA4 audit checklist. Run a 60-second audit to verify your Shopify attribution setup.

Travis Gunn
Travis Gunn
Founder of GA4 Health Check. Working with Google Analytics since 2013, with over 250 clients audited across almost every industry vertical. 100% Job Success on Upwork for over a decade.