Google Ads API tightens conversion data rules
Advertisers who don’t migrate to the Data Manager API risk broken conversion tracking when Google tightens Ads API data rules in 2026.
The Google Ads API will no longer accept new adopters of session attributes or IP address data in conversion imports starting Feb. 2nd. Developers who already use these fields can continue for now, but Google is steering everyone toward the Data Manager API as the primary place to send complex conversion and user data.
Zoom out. Google is consolidating richer data ingestion into the Data Manager API, positioning it as the long-term home for session-level attributes and IP-based signals. The Ads API is increasingly focused on core campaign and conversion workflows rather than handling complex data payloads.
Why we care. This change can directly affect whether conversions are successfully recorded. If session attributes or IP data are blocked, conversions may fail or lose important context, which can impact reporting, attribution, and automated bidding. Moving to the Data Manager API ensures continuity of measurement, access to richer data signals, and alignment with Google’s long-term measurement infrastructure.
Who’s affected. New developers will be blocked from sending session attributes or IP addresses via the Ads API. Existing developers who are already using these fields can continue temporarily, but access is controlled by developer-token allowlisting and migration is clearly expected.
What breaks. Once the change rolls out, some conversion imports may return a CUSTOMER_NOT_ALLOWLISTED_FOR_THIS_FEATURE error in partial-failure responses. That error means the conversion was rejected because it included session attributes or IP address data.
What to do: To resolve the issue, developers should temporarily remove session attributes and IP addresses from Ads API conversion imports, update their code to send that data through the Data Manager API instead, and then fully discontinue Ads API conversion imports once the Data Manager integration is working.
Bottom line: Google isn’t cutting off existing implementations immediately, but the direction is clear. If your conversion tracking depends on session attributes or IP data, migrating to the Data Manager API is no longer optional — it’s the path forward.
Dig Deeper. Changes to IP Address and Session Attribute Support in the Google Ads API
Search Engine Land is owned by Semrush. We remain committed to providing high-quality coverage of marketing topics. Unless otherwise noted, this page’s content was written by either an employee or a paid contractor of Semrush Inc.
About the Author
