Consent Mode v2 Complete Setup Guide for Google Ads

Consent Mode v2 is no longer optional. Since March 2024, Google requires it for any advertiser using Google Ads remarketing or audience features in the European Economic Area. If you’re running campaigns targeting the DACH market without it, you’re losing data, missing conversions, and potentially non-compliant with DSGVO regulations.

This guide covers what Consent Mode v2 is, why it matters for your Google Ads campaigns, and exactly how to implement it.

What Is Consent Mode v2?

Consent Mode is a framework that adjusts how Google tags behave based on the consent status of your website visitors. When a user declines cookies, instead of losing all data, Consent Mode sends cookieless pings to Google that enable behavioral modeling — Google can estimate conversions and user behavior without storing personal data.

Version 1 vs. Version 2

The original Consent Mode handled two consent signals:

• analytics_storage: Controls Google Analytics cookies
• ad_storage: Controls Google Ads cookies

Version 2 adds two new required signals:

• ad_user_data: Controls whether user data can be sent to Google for advertising purposes
• ad_personalization: Controls whether user data can be used for remarketing and personalized ads

All four signals must default to “denied” and update to “granted” only after explicit user consent.

Why DACH Businesses Must Implement This

Legal Compliance

The DSGVO (Datenschutz-Grundverordnung) requires explicit consent before processing personal data for advertising. Consent Mode v2 is the technical mechanism that aligns Google’s advertising products with this requirement.

Without it:

• You risk DSGVO non-compliance and potential fines
• Google restricts your access to remarketing audiences
• You can’t use Customer Match or similar audience features
• Enhanced Conversions won’t work properly

Data Recovery

In DACH markets, typical consent rates range from 40-70% depending on your CMP design, industry, and audience. Without Consent Mode, every visitor who declines cookies becomes invisible — no conversion tracking, no attribution, no optimization signals.

With Consent Mode v2 properly implemented, Google’s modeling fills in the gaps. Depending on your traffic volume and consent rates, you can recover 30-70% of the conversion data you’d otherwise lose.

Campaign Performance

Smart Bidding relies on conversion data. Less data means worse optimization. Consent Mode v2 feeds modeled conversions into Smart Bidding, keeping your automated strategies informed even when users decline consent.

Implementation: Step by Step

Prerequisites

Before starting, ensure you have:

1. A Google Ads account with active campaigns
2. Google Tag Manager (GTM) or gtag.js implemented
3. A Consent Management Platform (CMP) that supports Consent Mode v2
4. Access to your website’s code or CMS

Option A: Implementation via Google Tag Manager

This is the recommended approach for most businesses.

Step 1: Update Your CMP

Your CMP needs to communicate consent signals to Google Tag Manager. Major CMPs with built-in Consent Mode v2 support:

• Cookiebot: Enable “Google Consent Mode v2” in integration settings
• Usercentrics: Configure under Data Processing Services → Google
• OneTrust: Enable Google Consent Mode integration in cookie compliance settings
• Complianz: Built-in support in recent versions
• Borlabs Cookie: Consent Mode support available

Step 2: Configure Default Consent State in GTM

Add a Consent Initialization tag in GTM that fires before all other tags:

Tag Type: Consent Initialization - All Pages
Trigger: Consent Initialization - All Pages (built-in trigger)

Set default consent values:

• analytics_storage: denied
• ad_storage: denied
• ad_user_data: denied
• ad_personalization: denied
• wait_for_update: 500 (milliseconds to wait for CMP response)

Step 3: Configure Consent Update

When a user grants consent through your CMP, the consent state must update. Your CMP handles this automatically if properly configured — it pushes an update to the dataLayer that GTM reads.

Step 4: Enable Consent Mode in Google Tags

In GTM, each Google tag (GA4, Google Ads, Floodlight) must have Consent Mode enabled:

• Open the tag settings
• Under “Consent Settings,” select “Require additional consent for tag to fire” or use the built-in consent checks
• Map each consent type to the appropriate signal

Step 5: Verify Implementation

Testing is essential. Use these methods:

1. Google Tag Assistant: Visit your site, interact with the consent banner, and verify that tags fire correctly based on consent status
2. Browser DevTools: Check the Network tab for requests to google-analytics.com and googleads.g.doubleclick.net — they should include consent parameters
3. GTM Preview Mode: Walk through the consent flow and verify tag firing behavior

Option B: Implementation via gtag.js

If you’re using gtag.js directly (without GTM):

Step 1: Add Default Consent Before the Google Tag

Place this code in the <head> section, before your Google tag:

window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}

gtag('consent', 'default', {
  'analytics_storage': 'denied',
  'ad_storage': 'denied',
  'ad_user_data': 'denied',
  'ad_personalization': 'denied',
  'wait_for_update': 500
});

Step 2: Update Consent on User Action

When the user accepts cookies through your CMP:

gtag('consent', 'update', {
  'analytics_storage': 'granted',
  'ad_storage': 'granted',
  'ad_user_data': 'granted',
  'ad_personalization': 'granted'
});

Step 3: Configure Your CMP to Trigger the Update

Work with your CMP’s documentation to ensure it calls the consent update function when the user interacts with the banner.

Advanced Configuration

URL Passthrough

Enable URL passthrough to preserve ad click information across pages when cookies are denied:

gtag('set', 'url_passthrough', true);

This appends click identifiers (gclid, dclid) to URLs, allowing Google to attribute conversions even without cookies. Essential for high-consent-decline audiences.

Ads Data Redaction

Control whether ad click identifiers in network requests are redacted when consent is denied:

gtag('set', 'ads_data_redaction', true);

When enabled, ad click information is removed from requests when ad_storage consent is denied. This provides an extra layer of privacy compliance.

Region-Specific Defaults

If you serve both EEA and non-EEA audiences, set different defaults by region:

gtag('consent', 'default', {
  'analytics_storage': 'denied',
  'ad_storage': 'denied',
  'ad_user_data': 'denied',
  'ad_personalization': 'denied',
  'region': ['DE', 'AT', 'CH']
});

gtag('consent', 'default', {
  'analytics_storage': 'granted',
  'ad_storage': 'granted',
  'ad_user_data': 'granted',
  'ad_personalization': 'granted',
  'region': ['US']
});

Impact on Google Ads Campaigns

What Changes for Remarketing

Without Consent Mode v2, Google blocks remarketing audience building in the EEA entirely. With it implemented:

• Users who consent are added to remarketing lists normally
• Users who decline are excluded from remarketing lists
• Modeled audiences fill in some of the gap
• Overall remarketing audience sizes will be smaller but more compliant

What Changes for Smart Bidding

Smart Bidding needs conversion data to optimize. Consent Mode v2 allows Google to model conversions from non-consenting users, keeping the bidding algorithm informed.

Without Consent Mode:

• 30-60% of conversions may go untracked
• Smart Bidding makes decisions on incomplete data
• CPA targets become unreliable

With Consent Mode:

• Modeled conversions supplement observed data
• Smart Bidding optimization remains effective
• CPA and ROAS targets stay meaningful

What Changes for Reporting

Expect to see modeled data in your reports. Google Ads and GA4 will show a combination of observed (consented) and modeled (non-consented) conversions. This means:

• Conversion numbers will be higher than observed-only data
• Some metrics will include a “modeled” indicator
• Report accuracy depends on traffic volume (more traffic = better modeling)

Verifying Your Implementation

Essential Checks

Common Implementation Mistakes

1. Default state set to “granted” — This violates DSGVO requirements. Default must always be “denied”
2. Missing wait_for_update — Without it, tags may fire before the CMP loads, resulting in wrong consent state
3. Only implementing analytics_storage and ad_storage — Missing the v2 signals (ad_user_data, ad_personalization) means you’re on v1, not v2
4. Not testing across browsers — Consent Mode behavior can vary between Chrome, Firefox, and Safari
5. CMP not properly connected to GTM — The CMP must push consent updates to the dataLayer

CMP Optimization for Better Consent Rates

Since Consent Mode recovers data from non-consenting users through modeling, the best strategy is combining good consent rates with proper modeling:

• Design matters: A clean, clear banner converts better than a dark-pattern wall
• Layer the choice: Accept All / Manage Preferences / Reject All — in that order
• Language: Use clear German (DACH audiences respond to straightforward language)
• Timing: Show the banner immediately, don’t delay it
• Mobile optimization: Consent banners that cover the full mobile screen frustrate users

Next Steps After Implementation

1. Monitor consent rates — Track what percentage of users consent over the first 30 days
2. Compare conversion data — Check observed vs. modeled conversion ratios
3. Adjust Smart Bidding — Give bidding strategies 2-3 weeks to adapt to the new data signals
4. Review remarketing audiences — Verify audiences are building correctly
5. Set up ongoing monitoring — Consent rates and modeling accuracy should be checked monthly

For more on tracking and measurement setup, see our tracking services. If you’re also setting up server-side tracking, our GTM server-side tracking guide covers the full implementation.

Need help implementing Consent Mode v2 for your Google Ads campaigns? We handle the full setup — CMP configuration, GTM implementation, verification, and ongoing monitoring. Contact us for a consultation.