Consent Mode v2: what it is and why it matters

What Consent Mode v2 adds

The original Consent Mode had two parameters: analytics_storage and ad_storage. Consent Mode v2 adds two new required parameters:

• ad_personalization — controls whether data can be used for personalised advertising.
• ad_user_data — controls whether user data can be sent to Google for advertising purposes.

These two parameters are required by Google's EU User Consent Policy (EUCP). Properties that don't implement them are effectively sending all four consent parameters as "denied" from Google's perspective, which disables conversion modelling.

Why Google requires it for EU users

Under the GDPR and ePrivacy Directive, user consent must be collected before processing personal data for advertising. Google's EU User Consent Policy, updated in 2024, requires all partners using Google Ads products in the EEA and UK to implement CMv2. Failure to do so blocks access to audience features, conversion modelling, and enhanced conversions for those users.

How GA4 Audits checks for CMv2

The Tag & Consent Validation module uses a headless browser to visit your site and observe the gtag('consent', 'default', {...}) call. It checks that all four parameters are present and that the default state is set before the GA4 measurement tag fires. It also checks that the gtag('consent', 'update', {...}) call is triggered after the user makes a consent choice.

Checking if your CMP supports CMv2

Most major CMPs (OneTrust, Cookiebot, Usercentrics, CookieYes, Didomi, TrustArc) have added CMv2 support. The key is whether your CMP has been configured to send the two new parameters, not just whether the CMP vendor claims support.

Check your CMP's admin panel for a "Google Consent Mode v2" or "Advanced Consent Mode" setting. If you're using a CMP via GTM, check whether the CMP tag template has been updated to v2. GA4 Audits' crawl will confirm whether the signals are being sent correctly from the browser's perspective, regardless of what your CMP documentation claims.