What Is Google's Additional Consent Mode?

Google Consent Mode and Google Additional Consent Mode are two data privacy settings, designed by Google to help Google and its product users align their consent choices with the EU data privacy regulations like the European General Data Protection Regulation (GDPR) and the Digital Markets Act (DMA).

Even if both consent modes sound similar, Google Consent Mode and Google's Additional Consent Mode are separate technical specifications that serve totally different purposes.

In this guide, we’ll explain what Google’s Additional Consent Mode is, who is required to set it up, and how the two consent modes differ.

Both consent modes are necessary if you want to use Google Ads products for your advertising in the EEA markets.

What Is Google's Additional Consent Mode?

Google's Additional Consent Mode is a technical specification intended to work with IAB Europe's Transparency & Consent Framework (TCF) v2.2. It is used for managing consent for Google Ad Tech Providers (ATP) and enables websites to send user consent signals to vendors that are not yet registered with the IAB Europe Global Vendor List but are included in Google ATP list. 

Google's Additional Consent Mode allows websites implementing the TCF v2.2 wider access to publishers, Consent Management Platforms (CMPs), and agencies. Websites can collect and transmit consent choices to a broader set of vendors, allowing them to comply with privacy laws.

Read more about the related topics:

• What is Google Consent Mode v2?    
• What is IAB TCF and the latest updates IAB TCF v2.2. 
• What is a Google-certified CMP? 

To implement Google Consent Mode v2 and IAB TCF v2.2, you must use a Google-certified CMP such as CookieScript.

Is It necessary to use Google's Additional Consent Mode?

Google's Additional Consent Mode is important for the following reasons:

1. It allows compliance with the EU data privacy laws.
2. It enables websites to collect consent from a broader range of ad tech providers.

First, compliance with EU data privacy laws such as the GDPR and DMA is necessary for publishers using Google’s ad products. Without respecting user consent selection, websites can’t use Google Ads products such as AdSense, AdMob, and Ad Manager.

Second, Google's Additional Consent Mode also allows collecting consent from a broader range of ad tech providers, potentially leading to increased ad revenue. If consent for ad personalization is not obtained, Google will serve non-personalized ads or will not serve ads at all to EU users. This can seriously impact your ad revenue.

Thus, if you want to use Google ads services such as Google AdSense, AdMob, and Ad Manager in the EEA market by using vendors that are included in the Google ATP list but are not yet registered with the IAB Europe Global Vendor List (GVL), you need to use Google's Additional Consent Mode.

By implementing Google's Additional Consent Mode, you can continue serving personalized ads to your users, reach a broader range of ad tech providers, and comply with data privacy laws.

Google’s Additional Consent Mode Technical Specification

Google’s Additional Consent  introduces the “Additional Consent” (AC) string.

The “Additional Consent” (AC) string has the following format:

1. A specification version number, such as "2"
2. A separator symbol "~"
3. A dot-separated list of user-consented Google Ad Tech Provider (ATP) IDs. Example: "1.35.41.101"
4. A separator symbol "~"
5. "dv." followed by a dot-separated list of disclosed Google Ad Tech Provider (ATP) IDs. Example: "dv.9.21.81"

In this case, the AC string example would be 2~1.35.41.101~dv.9.21.81. The AC string 2~1.35.41.101~dv.9.21.81 means that the user has consented to ATPs with IDs 1, 35, 41 and 101, ATPs with IDs 9, 21, and 81 have been disclosed to the user and the string is created using the format defined in the v2 specification.

The AC string is significant because it stores the user consent information for Google ATPs.

Changes for Additional Consent

Google started to support Additional Consent specification since December 2023.

This update includes:

• Changes to the Additional Consent (AC) string to support vendors disclosed in the CMP.
• Modifications to the CMP API for interoperability for CMPs that support both TCF and Advertiser Consent Mode.

The AC string specification defines the following:

1. The AC string format.
2. The extension to the TCF v2.2 CMP API to support the AC string and controls for when both TCF and Advertiser Consent Mode are present.
3. The method to store an AC string.
4. The method to pass the AC string through the digital advertising chain.

Who can create an AC string?

Only IAB Europe TCF-registered CMPs like CookieScript CMP can create an AC string using their assigned CMP ID number in accordance with the IAB Policies. Vendors or any other third-party service providers can’t create AC strings themselves.

The AC string plays an important role in informing Google and its ATPs about the user’s consent preferences, enabling the delivery of personalized ads in compliance with the user’s choices and data privacy laws.

Differences Between Google Consent Mode and Additional Consent Mode

There are several notable differences between Google Consent Mode v2 and Google’s Additional Consent Mode:

1. Google Consent Mode v2 has data mapping features like Behavioral Modeling and Conversion Modeling that allow to fill in gaps in missing data when users decline consent for analytics and targeted ads. Google’s Additional Consent Mode uses neither Behavioral Modeling nor Conversion Modeling.
2. Google Consent Mode v2 impacts both Google Ads (Google AdSense, AdMob, and Ad Manager) and Google Analytics 4, while Google’s Additional Consent Mode impacts only Google Ads (Google AdSense, AdMob, and Ad Manager).
3. Google’s Additional Consent Mode is only relevant if your website implements IAB Europe’s TCF v2.2, a voluntary framework.
4. Google’s Additional Consent Mode communicates consent signals to vendors that are part of Google’s Ad Tech Provider’s list but aren’t yet part of the TCF Global Vendor list. 

Similarities Between Google Consent Mode and Google’s Additional Consent Mode

Google Consent Mode v2 and Google’s Additional Consent Mode also share similarities:

1. Both modes help websites better align consent requests for targeted ads and analytics and comply with EU data privacy laws like the GDPR and DMA.
2. Both modes use Google Tags (not internet cookies) to communicate user consent preferences with third-party service providers.
3. Website owners have to use a Google-certified CMP partner to implement both modes.
4. Google requires websites that serve ads in the EU/EEA to use a CMP that implements both Google Consent Mode and Additional Consent.

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Role of Consent Management Platforms (CMPs)

Any website that wants to use Google Ads or Google Analytics 4 for their advertising in the EEA markets must implement a cookie banner integrated with Google Consent Mode v2 by March 2024. A Google-certified CMP must be used to implement Google Consent Mode v2.

Websites using an IAB TCF v2.2 standard, that want to manage consent for Google Ad Tech Providers (ATP) and enable user consent signals to vendors that are not yet registered with the IAB Europe TCF Global Vendor list but are included in the Google’s Ad Tech Provider’s list, must implement Additional Consent Mode.

A CMP plays a significant role in managing user consent and creating the AC string for Google’s Additional Consent Mode. Only IAB Europe TCF-registered CMPs can create the AC string, ensuring that the process aligns with industry standards and best practices.

CookieScript CMP supports both Google Consent Mode v2 and Google’s Additional Consent Mode.

CookieScript CMP is a Google-certified CMP, included in the Google’s list of certified CMPs, and a TCF-registered CMP. It can be easily integrated with your IAB TCF v2.2 Cookie Banner.

CookieScript CMP allows you to work with a wider range of ad tech providers and increase your revenue by enabling compliance with global privacy regulations.

Moreover, in 2024, users on G2 ranked CookieScript CMP as the best CMP for small and medium-sized companies.

Frequently Asked Questions

What is Google’s Additional Consent Mode?

Google's Additional Consent Mode is a technical specification intended to work with IAB TCF v2.2. It is used for managing consent for Google Ad Tech Providers (ATP) and enables websites to send user consent signals to vendors that are not yet registered with the IAB Europe Global Vendor List but are included in Google ATP list. Only a Google-certified CMP like CookieScript CMP could be used to implement Google's Additional Consent Mode.

Who must use Google’s Additional Consent Mode?

Websites using an IAB TCF v2.2 standard, that want to manage consent for Google Ad Tech Providers (ATP) and enable user consent signals to vendors that are not yet registered with the IAB Europe Global Vendor List (GVL) but are included in the Google ATP list, need to use Google’s Additional Consent Mode. A Google-certified CMP like CookieScript CMP must be used to implement Additional Consent Mode.

Who must use Google Consent Mode?

Any website that wants to use Google Ads for their advertising or Google Analytics 4 in the EEA markets must implement Google Consent Mode v2 by March 2024. A Google-certified CMP like CookieScript CMP must be used to implement Google Consent Mode v2.

Who can create an AC string for Google’s Additional Consent Mode?

Only IAB Europe TCF-registered CMP like CookieScript can create an AC string using its assigned CMP ID number by the IAB Policies. Vendors or any other third-party service providers can’t create AC strings themselves.

Where are Google’s ATPs published?

Google publishes the list of Ad Tech Providers (ATP) not registered with the IAB and their IDs, and the list of all Google’s Ad Tech Providers. Use a Google-certified CMP like CookieScript to implement Google’s Additional Consent Mode if you want to use Google’s ATPs. The IAB TCF V2.2 also publishes the comapnies registered with the IAB TCF on the IAB Europe Global Vendor List. CookieScript CMP is a Google-certified CMP and a TCF-registered CMP.

Where are IAB TCF Global Vendors published?

IAB TCF Global Vendors are published on the TCF Global Vendor list.  Use an IAB Europe TCF-registered CMP like CookieScript CMP to implement Google’s Additional Consent Mode.

Is it necessary to use Google's Additional Consent Mode?

If you want to use Google ads services such as Google AdSense, AdMob, and Ad Manager in the EEA market by using vendors that are included in the Google ATP list but are not yet registered with the IAB Europe Global Vendor List (GVL), you need to use Google's Additional Consent Mode. By implementing Additional Consent Mode, websites can continue serving personalized ads to their users, reach a broader range of ad tech providers, and comply with the data privacy laws. You need to use an IAB Europe TCF-registered CMP like CookieScript to implement it.