What is Google’s Additional Consent?

Google’s Additional Consent is a technical specification that works alongside the IAB Europe Transparency and Consent Framework (TCF) v2. It communicates transparency and consent signals for Google Ad Tech Providers (ATPs) that are not registered on the IAB’s Global Vendor List (GVL).

Additional Consent uses an addtl_consent (AC) string containing the IDs of relevant Google ATPs and their consent or disclosure status. Additional Consent v2 (ACv2) is the current specification. A disclosed provider is not necessarily a consented provider.

The AC string supplements the TCF’s TC string; it does not replace it. Google processes Additional Consent as an extension of the TCF implementation, and an AC string should not be used without a corresponding TC string.

Only an IAB Europe TCF-registered CMP can create an AC string. Vendors and other third-party service providers should not create AC strings themselves.

Additional Consent vs. Consent Mode

Additional Consent and Google Consent Mode serve different purposes:

• Additional Consent: Communicates consent and disclosure information for non-GVL Google ATPs alongside IAB TCF.

• Consent Mode: Communicates consent signals that control how Google tags behave, including storage, advertising data use, and ad personalization.

Additional Consent therefore concerns advertising technology providers, while Consent Mode concerns Google tag behavior.

Additional Consent does not itself obtain legally valid consent or make a website compliant with privacy laws. The CMP and publisher remain responsible for collecting and handling consent appropriately.

See Google’s Additional Consent technical specification for the current ACv2 specification.