The IAB TCF (Transparency and Consent Framework) is a framework developed by IAB Europe that standardizes how user consent is collected in online advertising and communicated to the advertising ecosystem. Consent preferences are carried in an encoded string called the TC String and shared with partners registered on the Global Vendor List. The current version is v2.3, which replaced v2.2 in February 2026.
The TCF was developed by IAB Europe to standardize the consent needs of programmatic advertising under GDPR and ePrivacy rules. The framework has three main roles: CMPs (consent management platforms) that collect consent, vendors that process data, and publishers. Which purposes and which vendors the user has consented to is stored in a standardized code called the TC String and passed to the parties in the advertising chain. Vendors are registered on the Global Vendor List (GVL) managed by IAB Europe.
In practice, the TCF is critical for publishers earning programmatic advertising revenue: platforms such as Google AdSense and Ad Manager require a certified CMP for users in the European Economic Area, the UK and Switzerland. Without a valid TC String, many advertising partners cannot bid or serve personalized ads, which translates directly into lost revenue. Version 2.2 tightened the rules by making consent the basis for personalized advertising purposes and clarified the standards for user-facing texts; version 2.3, which replaced it in February 2026, is the current version of the framework. Not every site needs the TCF: for a corporate site using only its own analytics and marketing tools, a standard cookie banner may be sufficient. If you work with programmatic ad networks, check your partners' TCF requirements and use a TCF-enabled CMP.
Frequently asked questions
Who needs the IAB TCF?
Primarily publishers with programmatic advertising revenue: if you show ads to users in the European Economic Area, the UK or Switzerland through Google AdSense, Ad Manager or other ad networks, you are expected to use a certified, TCF-enabled CMP. For sites that use no ad networks and only run their own analytics and marketing tools, a standard cookie consent banner is sufficient in most cases.
What is a TC String?
The TC String (Transparency and Consent String) is the machine-readable, encoded form of the user's consent preferences. It records which purposes were consented to, which vendors may process data and which CMP collected the consent. It is generated by the CMP, stored on the user's device and passed to parties in the advertising chain; ad partners may process user data only according to the permissions in this string.
This content is for information only and is not legal advice.