In GA4 you see your own domain — or a payment gateway — as the visit source. That's a self-referral, and it's a problem: it breaks the visitor's session and the original source (campaign) is lost. Here's why it happens.
Why self-referral arises
When a visitor moves between your domains (or to a payment gateway and back) and cross-domain measurement isn't configured, GA4 reads it as arriving from another site — that second domain. A new session starts with source "your-domain.com / referral" and the original campaign detaches.
Symptoms
- Your own domain or the payment gateway's domain appears among traffic sources.
- Conversions are credited to "referral" instead of the original campaign.
- The session count rises and average journey length falls.
How to fix it
- 1. Configure cross-domain for all your domains so GA4 treats them as one site. Context in cross-domain tracking.
- 2. Add to the referral exclusion list the domains you don't want as a source (your own domain, the payment gateway).
- 3. Verify that transitions between domains preserve identity (linker / shared identification).
How to verify the fix
After fixing it, walk the journey across all domains and confirm the session stays one and the source doesn't change to your own domain. This relates to GA4 (not set) / direct instead of the source.