Google AdMob launches consent syncing for apps using European CMP

Google AdMob on November 10, 2025 introduced consent syncing for applications using its Consent Management Platform with European regulations messages. The feature synchronizes user consent decisions across multiple apps, eliminating redundant consent prompts that users encounter when accessing different applications from the same publisher.

According to the announcement, consent syncing becomes available for publishers who use European regulations messages in the Google CMP and have multiple apps with overlapping users. Publishers must pass a cross-app user ID to Google through the User Messaging Platform SDK to enable the functionality. The system aims to reduce consent fatigue by storing user decisions and applying them across app portfolios.

The technical implementation relies on unique consent sync identifiers combined with the Google User Messaging Platform SDK to confirm previous consent decisions. When a user makes a consent decision in one application within a defined consent group, that decision transmits via the UMP SDK to a consent server where it stores alongside the assigned consent sync identifier. Subsequent initializations of other apps in the group send the identifier to the consent server for comparison against existing identifier-consent string combinations.

The system processes valid consent decisions by fetching and storing the Transparency and Consent string locally without displaying the European regulations message. When no valid consent decision exists on the server, the application displays the message and uploads the new decision along with the user's consent sync identifier. Changes made to consent settings in one application apply to other apps in the consent group during the next requestConsentInfoUpdate call through the UMP SDK.

Publishers must create consent groups before syncing can begin. Only apps with published European regulations messages qualify for inclusion, while messages using in-ad-unit deployment remain ineligible. Google's CMP launched support for consent mode in March 2025, enabling consent choices to flow across Google's product ecosystem.

The consent sync identifier must uniquely identify users across all apps where consent syncs, requiring hashing or encryption to prevent transmission of personally identifiable information. The identifier must construct as a UUID string or match the regular expression ^[0-9a-zA-Z+.=/_-$,{}]{22,150}$ with minimum 22 characters and maximum 150 characters. Failure to meet requirements results in the UMP SDK discarding the identifier and logging console warnings.

Privacy policies must explicitly list all apps in the consent group that will share consent decisions. Apps can become ineligible by deleting their European regulations message but remain in the consent group until eligibility restores. Consent won't sync for ineligible apps during that period. The European regulations messages displayed in member apps inform users that their consent decisions apply to a group of apps and link to the privacy policy.

The system handles consent conflicts by comparing timestamps between locally-stored and server-stored Transparency and Consent strings. When the locally-stored TC string contains a more recent LastUpdated timestamp than the server version, the local string overrides the server version. If the server-stored TC string has a more recent or identical timestamp, it overwrites the locally-stored version.

Consent revocation operates across the entire consent group when enabled. Users who revoke consent for one app revoke consent for all apps in the group. Publishers must provide a link in app menus allowing users to revoke previous consent decisions under GDPR requirements. German court rulings on cookie consent have emphasized that personal data processing for commercial purposes requires explicit consent or compelling legitimate interests that don't override user privacy rights.

Publishers can request deletion of stored TC strings for specific users through a web endpoint. The deletion request requires a POST request to https://fundingchoicesmessages.google.com/csd?userid={user's_ID}&appid={one_of_the_appids_in_the_consent_group} with URL-encoded parameters.

The feature addresses mounting privacy compliance complexity in the mobile advertising ecosystem. Every advertiser in the EEA needs a Consent Management Platform to comply with the General Data Protection Regulation and ePrivacy Directive requirements. Google's EU user consent policy mandates that users provide explicit consent for personal data sharing with Google for advertising purposes.

Publishers access the feature through their Privacy & messaging settings in the AdMob console at admob.google.com. The consent syncing section allows selection of apps to include in consent groups, with confirmation saving the group configuration. The system automatically enables features by default across applications, with security considerations including automatic adjustments for child-directed applications under Google Play's Families policy.

Mobile app publishers face increasing regulatory requirements across jurisdictions. Google mandated TCF v2.3 migration by February 2026, requiring updated technical implementations for handling user consent strings in digital advertising. The Transparency and Consent Framework applies to Google's advertising products including AdSense, Ad Manager, AdMob, Authorized Buyers, and Open Bidding across the European Economic Area, United Kingdom, and Switzerland.

The consent syncing feature enters a complex regulatory landscape where India recently launched comprehensive data protection rules with consent managers establishing frameworks distinct from European and American approaches. The Digital Personal Data Protection Rules 2025 introduce consent managers as registered intermediaries responsible for enabling data principals to control personal information processing.

AdMob continues expanding privacy infrastructure alongside monetization tools. Google rolled out policy center improvements in April 2025 with new classification labels helping app publishers identify and prioritize ad serving issues. The platform categorizes issues into policy, regulatory, and advertiser preference types with specific labels replacing previous "Must fix" designations.

Publishers implementing consent syncing should review implications for revenue optimization. The announcement states that minimizing consent fatigue can increase user engagement and potentially boost ad revenue. Applications already open on user devices may require restart before consent decisions apply, creating temporary discrepancies during the synchronization process.

Timeline

• July 2021: Google introduced app open ad format in AdMob for previously untouched inventory
• January 2024: Google launched Technical Ad Delivery on AdMob for traffic without consent
• March 2024: Every advertiser in EEA needs Consent Management Platform for GDPR compliance
• May 2024: Google AdMob unveiled tools for app publishers to leverage first-party data
• July 2024: German court ruling on cookie consent determined Google Tag Manager requires explicit user consent
• August 2024: Google Tag Manager introduced Consent Mode Override Setting for enhanced privacy controls
• September 2024: New Consent Parser Tool launched simplifying data consent management
• March 2025: Google's CMP launched support for consent mode enabling consent choices across Google products
• April 2025: Google rolled out policy center improvements in AdMob with new issue classification
• November 3, 2025: Google mandated TCF v2.3 migration by February 2026 for consent framework compliance
• November 10, 2025: Google AdMob launched consent syncing for apps using European CMP
• November 13, 2025: India launched comprehensive data protection rules with consent managers

Summary

Who: Google AdMob publishers operating applications in the European Economic Area, United Kingdom, and Switzerland who use European regulations messages in the Google Consent Management Platform with multiple apps serving overlapping user bases.

What: Cross-app consent syncing feature that synchronizes user consent decisions across multiple applications within publisher-defined consent groups, eliminating redundant privacy prompts by storing Transparency and Consent strings on centralized servers accessible through unique consent sync identifiers passed via the User Messaging Platform SDK.

When: Announced November 10, 2025, with immediate availability in beta for publishers who configure consent groups through Privacy & messaging settings at admob.google.com and implement proper consent sync identifiers meeting technical requirements of 22-150 characters matching specified regular expressions.

Where: Available through Google AdMob platform for applications serving users in regions requiring European regulations messages under GDPR and ePrivacy Directive compliance, accessed through publisher accounts at admob.google.com and implemented through integration with User Messaging Platform SDK in Android and iOS applications.

Why: Reduces consent fatigue by eliminating repetitive privacy prompts across multiple applications from the same publisher, potentially increasing user engagement and ad revenue while maintaining compliance with European data protection regulations requiring explicit user consent for personal data processing and cookie usage in digital advertising.