What is Consent Mode v2, and how do you set it up?

Consent Mode is a signal layer that determines how Google tags behave when a user has not given cookie consent. Two new parameters arrived with v2: ad_user_data and ad_personalization.

Why did it become mandatory?

When Consent Mode v2 signals are not sent for users in the European Economic Area, Google Ads remarketing lists stop filling and conversion modelling is disabled. E-commerce sites advertising from Turkey but selling into Europe are affected directly.

The three mistakes made most often during setup

1. Leaving the default as "granted". The default state of Consent Mode must be denied. If a measurement cookie is written before consent is obtained, the setup does not count as compliant.

2. Loading the banner after the tags. The consent management platform must run before the Google tags; otherwise the first page view is measured without consent.

3. Not storing consent persistently. Once a user has given consent they should not be asked again on later visits; the stored preference must be restored with a consent update.

Verification

After setup, check the consent state of every tag one by one through Google Tag Assistant. Data usually takes about seven days to start appearing under "Behavioural modelling" in the GA4 interface.