PayPal takes the credit for your sales: payment gateways as referrals in GA4
If paypal.com shows up as the source of your purchases, the return from the gateway is being logged as new traffic. The unwanted referrals list fixes it.
- A user arrives from Google, goes through checkout and pays on PayPal before coming back to the thank-you page.
- GA4 credits the purchase to paypal.com / referral, not to the organic search that started it.
- The cause: coming back from the gateway, the payment domain is recorded as a new traffic source.
- The fix: add the gateway domains to the list of unwanted referrals.
- Check purchases by source / medium over the next days. The change does not fix past data.
In many online shops, payment is completed off-site: the user goes to PayPal, to a bank’s payment page or to a form hosted by the gateway, and comes back to the site to see the confirmation. That round trip is invisible to the user, but not to GA4, which sees a new visit arriving from another domain right before the purchase.
What payment gateway referrals look like in GA4
In the acquisition report, or when you look at purchases by source / medium, paypal.com / referral, checkout.stripe.com / referral or your bank’s domain show up with a surprisingly high share of sales. The channels that actually brought the customer, such as organic search or a campaign, lose those conversions.
Why PayPal and Stripe show up as referrals
When the user comes back from the gateway, the confirmation page loads with the gateway’s domain as the referrer. GA4 reads it as a new traffic source. Even if that new source doesn’t start a separate session, it becomes the user’s most recent source, and the key event attribution model gives it the credit for the purchase that follows.
It is a property configuration mistake, not a site code one: the tag does exactly what it should with the information it receives.
How to find payment gateways in your traffic sources
- In Reports → Acquisition → Traffic acquisition, add the
purchasekey event and sort by source / medium. Look for payment, bank or authentication provider domains. - Check the journey: if the gateway only appears in sessions that end in a purchase, this is almost certainly the problem.
- In the Network tab, when you come back from the gateway, the confirmation page hit carries the gateway’s domain in the referrer parameter (
dr).
How to exclude payment gateways with unwanted referrals
Add the gateway domains to the web stream’s list of unwanted referrals:
- Admin → Data streams and select the web stream.
- Configure tag settings → Show all → List unwanted referrals.
- Create one condition per domain, for example Referral domain contains
paypal.com, and repeat for every gateway, payment terminal or external sign-in (SSO) provider that sends users back to your site.
With this setting, GA4 ignores that referrer and the purchase keeps its original source.
Google’s documentation: Identify unwanted referrals.
How to check the purchase keeps its real source
- Make a test purchase that goes through the gateway and check in DebugView that the confirmation
page_viewdoesn’t bring a new source. - Over the following days, purchases credited to the gateway should disappear from the reports.
- The change is not retroactive: earlier purchases stay credited to the gateway. If you analyse long periods, note the date of the fix.
Keep the list up to date: every time a payment method or an authentication provider is added, a new domain appears that can bring the problem back.