The GA4 Referral Exclusion List (called Unwanted Referrals in GA4) solves a specific attribution problem: sessions that are restarting mid-funnel because a user passes through a domain that GA4 mistakenly treats as the source of a new session. Every time this happens, your original campaign attribution is replaced by the intermediate domain as the referral source. Understanding when to add a domain to this list, and crucially when not to, prevents both the original attribution problem and the new problems that come from misusing the exclusion list.
What unwanted referrals does
When GA4 sees a session start with a referrer matching a domain in yourUnwanted Referrals list, it ignores that referrer and continues the existing session instead of starting a new one. The user'soriginal traffic sourceis preserved.
For example: a user arrives from an email campaign (utm_source=email). Mid-purchase, they are redirected through your payment provider's domain (payment.provider.com). When they return to your confirmation page, GA4 sees payment.provider.com as the referrer and starts a new session attributed to payment.provider.com — exactly the situation that createssource/medium flipping mid-funnel. Your email campaign loses the conversion.
Adding payment.provider.com to Unwanted Referrals tells GA4: when a session starts with this referrer, do not treat it as a new source. Extend the existing session. Your email campaign retains the conversion.
When to use unwanted referrals
- Payment processors: PayPal, Stripe, Klarna, Afterpay, Worldpay, Opayo (formerly Sagepay), and any other domain users pass through during payment that redirects back to your site
- Third-party checkout tools: any SaaS checkout domain that is separate from your main store domain
- Login providers: OAuth domains like accounts.google.com or auth0.com if your site uses single sign-on and the authentication flow redirects through an external domain
- Your own secondary domains: if cross-domain tracking is configured but a domain still appears in your referral report
- External booking or scheduling tools: Calendly, Acuity, or similar tools where the user leaves your domain to book and returns to a confirmation page
When NOT to use unwanted referrals
The Unwanted Referrals list is often misused by adding domains that should be legitimate referral sources. Adding google.com to the list would strip Google as a referral source from sessions that genuinely came from organic search, causingorganic search traffic to inflate Direct.
Do not add domains to the Unwanted Referrals list because you want to stop them appearing in your reports. The correct tool for that is the Traffic Sources report with filters, or a custom channel grouping. Unwanted Referrals is only appropriate for domains that appear as sources solely because a redirect passes through them.
Difference between unwanted referrals and cross-domain tracking
These two features address related but distinct problems and are not interchangeable.
Cross-domain tracking is for domains you own and want to treat as a continuous journey. It ensures the user's Client ID and session carry across from domain A to domain B via the _gl parameter — seehow GA4 counts sessionsfor the underlying mechanic. Use this for your own store and checkout domains.
Unwanted Referrals is for third-party domains you do not own but that appear as referral sources mid-funnel due to redirect flows. You cannot add a domain to your cross-domain list unless you have GA4 installed on it, which you cannot do for third-party payment providers.
Not sure which payment processors are hijacking your attribution?
How to add unwanted referrals
The steps below walk through adding domains to the unwanted referrals list via GA4 Admin. Changes take effect for new sessions only — existing data is not retroactively corrected, and the parameters captured at the original session start (such as those used in yourpurchase event parameters) will already be locked in.
Open admin > data streams
In GA4, click Admin in the bottom-left. Under your property, select Data Streams. Click on your web data stream.
Open configure tag settings
Scroll down to the More tagging settings section and click Configure tag settings. This opens the tag configuration panel where referral exclusions live.
Open list unwanted referrals
Click List unwanted referrals from the configuration options. You will see any domains already excluded.
Add each domain
Click Add condition. Set the match type to Contains. Enter the root domain (e.g., paypal.com, klarna.com, stripe.com). Using Contains ensures subdomains of the payment provider are also covered.
Save and verify
Click Save. Changes apply to new sessions going forward. Run a test transaction through the payment provider and check the Traffic Acquisition report the following day to confirm the payment provider no longer appears as a session source.
Referral exclusion audit action plan
Validate
- Open Traffic Acquisition report and filter by Session source = referral, look for payment processors (stripe.com, paypal.com, klarna.com) appearing as session sources
- Check whether any of your own subdomains appear as referral sources, indicates cross-domain tracking is not fully configured
- Look for booking or scheduling tool domains (calendly.com, acuity) appearing as sources for sessions that convert
- Confirm conversions are not being attributed to stripe.com or paypal.com in your conversion source breakdown
Fix
- Add each payment processor domain to the Unwanted Referrals list using Contains match type
- Add external booking and scheduling tool domains that appear as mid-funnel referrers
- For your own domains, use cross-domain tracking (Configure your domains) rather than Unwanted Referrals
- If a login provider domain appears as a referrer, add it to Unwanted Referrals
Watch for
- Conversions attributed to stripe.com or paypal.com, these should disappear after adding those domains to Unwanted Referrals
- Direct traffic volume increasing after adding exclusions, this is expected as some previously-attributed sessions now continue correctly instead of restarting
- Affiliate or partner domains accidentally added to Unwanted Referrals, this would strip legitimate referral attribution from real traffic sources
Referral exclusion checklist
- All payment providers used on the site are listed in Unwanted Referrals
- Third-party checkout, booking, and scheduling tools are listed in Unwanted Referrals
- Login provider domains added if authentication flows redirect through them
- No legitimate external referral sources (affiliates, partner sites) are incorrectly added
- Cross-domain tracking used for your own domains, not Unwanted Referrals
- Traffic Acquisition report checked after changes to confirm payment provider domains no longer appear as session sources
- stripe.com and paypal.com are not appearing as conversion sources in attribution reports
Related guides to read next
GA4 Missing Purchase Events on Shopify
PayPal and BNPL payment flows cause missing purchases, how to diagnose and fix.
GA4 Source/Medium Changed to Direct
Why sessions lose their original source and how to prevent it.
GA4 Attribution Models Explained
How GA4 attributes conversions across touchpoints and which model fits your business.
Cross-Domain Tracking in GA4
Set up continuous session tracking across your own domains.
Find which domains are hijacking your conversion attribution
GA4 Audits checks your Traffic Acquisition report for payment processors and third-party tools appearing as referral sources and flags which ones need adding to your exclusion list.