What Is Consent Mode V2 and Do You Need It

If you advertise with Google in the European Economic Area, Consent Mode V2 is not optional. It has been a requirement since March 2024, and accounts without it lose access to features they may not realize they were using.

Plenty of businesses have heard the term, assumed their cookie banner covered it, and moved on. Frequently it does not. Here is what V2 actually is, what changed from V1, and how to tell whether you have it.

What consent mode V2 is and why Google announced it

Consent mode is the mechanism by which your website tells Google's tags what a user consented to. Rather than blocking tags outright when someone declines, it lets them run in a restricted state that respects the choice while still providing signals Google can model from.

V2 is an expansion of that framework. It adds two new signals specifically covering how user data may be used for advertising, and it makes implementation mandatory for advertisers serving users in the EEA and UK.

The driver is the Digital Markets Act, which requires designated gatekeepers, Google among them, to obtain and honor explicit end user consent before using personal data for advertising purposes. Google's response was to require advertisers to pass that consent signal explicitly, rather than assuming it.

The practical effect is that consent handling moved from a compliance nicety to a technical prerequisite for using large parts of the Google advertising stack.

The difference between V1 and V2

V1 established the framework with two signals:

• ad_storage, governing whether advertising cookies and identifiers may be stored
• analytics_storage, governing whether analytics cookies may be stored

Both are about storage. They answer the question of whether something may be written to the user's device.

V2 keeps both and adds two more:

• ad_user_data, governing whether user data may be sent to Google for advertising purposes
• ad_personalization, governing whether that data may be used for personalized advertising and remarketing

These are about use, not storage. That distinction is the whole point of the update. A user might allow a cookie to be set while not consenting to their data being used to build an advertising profile, and V1 had no way to express that difference.

The other change is enforcement. V1 was recommended. V2 is required for EEA and UK traffic, and the consequences of not having it are automatic rather than discretionary.

What the new V2 signals cover

ad_user_data answers whether you may send user data to Google for advertising purposes at all. When denied, Google Ads conversion tags cannot transmit user provided data such as hashed emails. This directly affects Enhanced Conversions and Customer Match, both of which depend on sending identifiers to Google for matching.

ad_personalization answers whether the data may be used to personalize advertising. When denied, that user cannot be added to remarketing audiences or used for personalized targeting. They can still be served contextual advertising.

Both are independent of the storage signals. A valid combination is storage granted, personalization denied: cookies may be set for measurement, but no advertising profile may be built.

Your consent banner needs to actually collect enough granularity to set these correctly. A banner offering only Accept All and Reject All can map both cases, but a banner with granular categories needs those categories mapped thoughtfully to the four signals.

What happens to your campaigns without V2

The consequences apply to EEA and UK traffic specifically, and they are cumulative.

Audience features stop working for affected users. Without ad_personalization granted, users cannot be added to remarketing lists. Existing audiences shrink over time as membership expires and is not replenished. Remarketing and Customer Match campaigns lose reach, gradually enough that the cause is easy to miss.

Conversion modelling becomes unavailable. Without proper consent signals, Google cannot model the conversions it did not directly observe. Your reported conversions reflect only consenting users, which understates performance and biases what smart bidding learns from.

Enhanced Conversions degrade. Without ad_user_data, the hashed first party data that improves match rates cannot be sent, so conversion matching quality falls.

Warnings appear in your account. Google surfaces consent mode warnings in Google Ads, though they are easy to overlook among other notifications.

None of this stops your ads serving. That is what makes it insidious. Campaigns keep running, reporting keeps producing numbers, and performance quietly degrades in ways that look like market conditions.

How to implement consent mode V2 with your existing CMP

You do not need to replace your consent platform. Most established CMPs already support V2 and simply need it enabled.

Confirm your CMP supports V2. Cookiebot, OneTrust, Complianz, Usercentrics, Axeptio and others all do. Check the version and that V2 mode is switched on, because many accounts are still running a V1 configuration.

Set the default state before any tags load. All four signals must default to denied before your GA4 or Google Ads tags execute. In Google Tag Manager this means using the Consent Initialization trigger, which fires before All Pages. This ordering is the most common point of failure, and getting it wrong produces a setup that looks correct while leaking data on first page load.

Map your banner categories to all four signals. Decide explicitly which of your consent categories grants ad_user_data and which grants ad_personalization. Do not assume the CMP defaults match your intent.

Fire the update command on user choice. When someone interacts with the banner, an update command must communicate the result to Google's tags.

Configure consent settings on non Google tags. Google tags read the signals automatically. Third party tags need consent requirements declared explicitly in GTM.

How to verify your implementation is working

Use GTM preview mode. Load your site and check the Consent tab. It shows the state of each signal at each step. Confirm all four default to denied on initial load, before any tags fire.

Test the decline path specifically. Reject consent and confirm Google tags still fire in restricted mode rather than not firing at all. If they do not fire, you have blocking rather than consent mode, and you are losing the modelling benefit entirely.

Test the accept path. Confirm all four signals flip to granted and tags switch to full behavior.

Check Google Ads. Look under Tools, then Data Manager, or in your account notifications, for consent mode diagnostics. Google reports whether it is receiving valid signals.

Watch modelled conversions appear. Once V2 is working and you have sufficient volume, modelled conversions show up in your GA4 and Google Ads reporting. Their presence is the clearest confirmation the implementation is functioning.

The short version

If you advertise to European users and have not explicitly confirmed V2 is implemented, assume it is not. Having a cookie banner is not the same thing, and the failure mode is silent degradation rather than an error message.

FAQ

What is Google Consent Mode V2?

Consent Mode V2 is Google's framework for communicating user consent to its tags, expanded with two new signals: ad_user_data, covering whether user data may be sent to Google for advertising, and ad_personalization, covering whether it may be used for personalized ads. It has been required for advertisers serving EEA and UK users since March 2024.

Do I need Consent Mode V2 if I do not advertise in Europe?

It is only mandatory for EEA and UK traffic, so a purely domestic business elsewhere is not required to implement it. It is still worth doing. Proper consent handling improves data quality wherever privacy regulations apply, and implementing it now avoids a rushed retrofit if you expand or if similar requirements arrive in your market.

What is the difference between Consent Mode V1 and V2?

V1 had two signals, ad_storage and analytics_storage, both governing whether data could be stored on the device. V2 adds ad_user_data and ad_personalization, which govern how data may be used rather than whether it may be stored. V2 is also mandatory for EEA and UK advertising, whereas V1 was recommended.

What happens if I do not implement Consent Mode V2?

For EEA and UK traffic you lose access to audience features, so remarketing lists stop being populated and shrink over time. Conversion modelling becomes unavailable, understating reported performance. Enhanced Conversions degrade because user data cannot be sent. Campaigns keep running throughout, which makes the decline easy to attribute to market conditions instead.

How do I check if Consent Mode V2 is set up correctly?

Open GTM preview mode and check the Consent tab. All four signals should default to denied before any tags fire, using the Consent Initialization trigger. Decline consent and confirm Google tags still fire in restricted mode. Then accept and confirm they switch to full behavior. Google Ads also surfaces consent diagnostics in the account.