What type of data can be collected when using a Google forwarding number with a call extension?

When using a Google forwarding number with a call extension, Google Ads can track call duration. This metric helps advertisers understand the engagement level of calls generated from their ads. While Google forwarding numbers facilitate call tracking, they do not collect personally identifiable information such as the caller's name or the caller's specific phone number (though the number is used to connect the call, it's not stored for advertiser access in a personally identifiable way). Call location is also not directly collected as a standard metric through this feature; instead, location targeting helps determine who sees the ad, but not the caller's precise location during the call itself.