If you’re using keyword pools, you'll have session-level call attribution. Session-level call tracking gives you a better view of the caller's interaction path that led to a phone call, including every source and page view that lead to a conversion.
How it Works
Let’s say a visitor comes to your website through a Google Ads advertisement. Two days later, they remember visiting your website and decide to visit again, this time finding your site by doing a Google Organic search. Five days later, they’re browsing the web and see your retargeting advertisement and visit your site using that link. With a keyword pool, you're able to see that the caller first came through Google Ads, then came back through Google Organic, and finally through your retargeting campaign.
Session-Level Attribution Data
You can find your session attribution data in two places:
Which source is reported to Google Analytics?
The first channel or source that a user came through is reported to Google Analytics.