If you advertise to visitors in the European Economic Area or the UK, Google requires you to pass consent signals with your tags. Consent Mode v2 is how you do it. Even outside those regions it is becoming the standard way to respect visitor choices without losing all measurement.
What changed in 2024
From March 2024 Google began enforcing its EU user consent policy for its ad products. Consent Mode v2 added two signals to the existing ad_storage and analytics_storage:
ad_user_data: whether user data can be sent to Google for advertising.ad_personalization: whether data can be used for personalised advertising such as remarketing.
Without these signals for EEA traffic, features like remarketing audiences and some conversion measurement are limited.
Basic vs advanced mode
- Basic: Google tags do not load at all until the visitor consents. Simple and conservative, but you get no data from people who decline, and modelling relies on general patterns.
- Advanced: tags load with consent denied by default and send cookieless pings. No cookies are set and no identifiers are stored, but Google can use those pings to model behaviour more accurately for your site.
Which one fits depends on your legal advice and risk appetite. Either way, the default state must be set before any tag fires.
How modelling recovers lost conversions
When visitors decline, GA4 and Google Ads use the behaviour of consenting visitors, plus cookieless pings in advanced mode, to estimate conversions that were not directly observed. GA4 behavioural modelling needs enough daily traffic to kick in, so smaller sites may not see modelled data. It narrows the gap; it does not close it.
A quick health check
- Your consent banner (CookieYes, Cookiebot or similar) is certified or integrated with Google consent mode.
- Default consent is set to denied for the regions that need it, before any tags load.
- Tag Assistant shows consent updating when you accept or reject.
- GA4 and Google Ads diagnostics show no consent mode warnings.
Unsure if your banner is actually talking to your tags? Book a free strategy call and we will take a look.
Want a quick health check first? Run our free tracking audit, it takes 20 seconds.