Any app in the Designed for Families program (or otherwise directed at children) is limited to serving ads through SDKs that have gone through Google's self-certification process confirming they don't collect data inappropriately from child users.
Commonly triggered when a kids' app integrates a general-purpose ad SDK that hasn't self-certified for the families program, often because the developer didn't check the certified-SDK list before integrating.
"Your app is directed at children but serves ads through an SDK that is not part of the Families Self-Certified Ads SDK Program, per Google Play's Families policy."
Apps in the Designed for Families programme, or otherwise directed at children, may only serve ads through SDKs that have completed Google's self-certification. The certification confirms that the SDK does not collect data from children in disallowed ways. A frequent cause of problems is integrating a general ad SDK without checking the certified list.
Children are not able to judge how their data is used, and advertising technology is built to collect information. Google therefore limits which ad tools can appear in children's apps and requires their providers to commit to child-safe practices. A certified list gives developers a clear set of options and gives Google a way to remove SDKs that break the commitments.
Google publishes the programme's certified SDKs in its policy resources.
It applies to apps in the programme and those directed at children.
Data collection from children has its own limits beyond ads.
Platform rules change often. This page is a plain-language explanation written by AppReviewFix, not official guidance. Check the current Google Play Developer Policy Center for the exact wording.