Unwanted Referrals in GA4: How to Exclude Klarna and PayPal

Many online stores send customers to Klarna, PayPal or Stripe when it is time to pay. When the customer comes back to the thank-you page, Google Analytics 4 sees a visit coming from the payment service. The sale can then end up credited to paypal.com or klarna.com in your reports instead of the ad or search that actually brought in the business.

This post explains how to check whether this is happening to you and how to set up the list of unwanted referrals. It also covers how the list relates to cross-domain measurement and why the change only applies going forward.

Why the payment service gets credit for the sale

A referral is a visit that arrives through a link from another website. GA4 records where the visitor came from and uses it when deciding which channel should get credit for a sale.

The problem arises when the customer leaves your website to pay and is sent back afterwards. It then looks as if the customer came from the payment service. According to Google's help page on unwanted referrals, a third-party payment processor is the typical example of when the list is needed.

The result is that Google Ads and organic search look weaker than they are. If you import purchases from GA4 into Google Ads, it can also affect what your bid strategies learn. How noticeable this is depends on which attribution model you use and on whether purchases are also measured with the Google Ads tag. You can read more about how bid strategies use conversions in the guide to bid strategies in Google Ads.

How to check whether you have the problem

You can check this in a few minutes in the standard reports.

1. Open Reports and go to Acquisition and then Traffic acquisition.
2. Change the first column to the dimension Session source / medium.
3. Search the table for rows such as paypal.com / referral, klarna.com / referral or checkout.stripe.com / referral.
4. Look at how many purchases or key events those rows have compared with the number of sessions.
5. Do the same for any other services in your checkout. This could be a card acquirer or the bank's verification of card payments.

In my assessment it is a clear sign when a payment service has a purchase in almost every session. Ordinary referrals from other websites rarely look like that. The domains vary by payment method and country, so start from what actually appears in your own report.

Service	Domain that may appear in the report	Suggested condition
Klarna	klarna.com	Ends with klarna.com
PayPal	paypal.com	Ends with paypal.com
Stripe	checkout.stripe.com	Ends with stripe.com

The Ends with condition also catches subdomains such as checkout.stripe.com. Only add domains you have seen in the report or know are part of your checkout.

How to set up the list step by step

You need at least the Editor role on the GA4 property to change the setting. Here is how:

1. Go to Admin and choose Data streams under Data collection and modification.
2. Click Web and select your web data stream.
3. Click Configure tag settings at the bottom.
4. Click Show all under Settings.
5. Select List unwanted referrals.
6. Choose a match type and enter the domain. Click Add condition for each additional domain.
7. Click Save.

The conditions are combined with OR logic, so a match on any one of them is enough. According to Google you can add up to 50 unwanted referrals per data stream.

Technically, GA4 adds the parameter ignore_referrer=true to events that match the list. This means the visit is not shown with the payment service as its source. The conditions are evaluated on every page where the Google tag is installed, so you do not need to change anything in Tag Manager.

Cross-domain measurement is a different setting

It is easy to confuse the list with cross-domain measurement. That setting is used when you own several domains yourselves and want a visitor to count as the same person across all of them. One example is an online store on one domain with the checkout on another.

For this to work, every domain must use the same Google tag with the same measurement ID. You add the domains under Configure your domains in the same tag settings menu. GA4 then passes the _gl parameter in the URL when the visitor moves between the domains. According to Google's help page on cross-domain measurement, the visit is then not counted as a referral.

Klarna, PayPal and Stripe do not have your tag on their pages. Cross-domain measurement does not work there, and the list of unwanted referrals is what applies. GA4 already excludes referrals from your own domain and its subdomains automatically.

The change only applies going forward

The list does not change data that has already been collected. Sales that have already been credited to PayPal or Klarna stay that way in the reports for earlier periods.

According to Google, the payment service may also keep appearing for a while after the change. A session that has already been attributed to the domain keeps that attribution. A returning customer can also have the sale credited to the domain, because in some reports GA4 gives credit to the last source that was not direct traffic.

Expect it to take a few weeks before the figures look clean. Note the date of the change so that nobody later reads the shift between channels as a real change. GA4 has an annotations feature in the reports that works well for this.

Check that it works

1. Make a test purchase with each payment method a few days after the change.
2. Open Traffic acquisition again and compare the period after the change with the period before.
3. Check that purchases now land on channels such as Paid Search and Organic Search.
4. Add new domains to the list if you switch or add a payment service.

The same report is used when you want to see how much traffic comes from ChatGPT and other AI services. How to do that is covered in the guide to tracking AI traffic in Google Analytics 4.

We review GA4 and Tag Manager and make sure sales are credited to the right channel. That covers payment services as well as consent and conversions for Google Ads. Read more about measurement and dashboards and about how we work with e-commerce and brands.

Which payment services are in your checkout today, and do any of them show up as the source of your sales in GA4?