What Is the IAB TCF
The Transparency and Consent Framework is an industry standard developed by IAB Europe that establishes a common protocol for communicating user consent choices across the digital advertising ecosystem. It provides a standardized way for publishers, advertisers, ad tech vendors, and consent management platforms to collect, store, and transmit consent signals so that every party in the programmatic advertising chain knows exactly what a user has agreed to.
TCF v2.2, the current version released in May 2023, tightened the requirements around legitimate interest, improved transparency for users, and aligned more closely with guidance from European data protection authorities. It replaced TCF v2.0 and is now the mandatory version for all participants in the framework.
The framework is built around a Global Vendor List that enumerates every registered ad tech vendor, the purposes for which they process data, and the legal bases they rely on. When a user interacts with a TCF-compliant consent banner, their choices are encoded into a Transparency and Consent String that travels with every ad request, ensuring that all vendors in the supply chain respect the user's preferences.
Why It Matters for Publishers and Advertisers
Publisher Revenue Protection
For publishers that monetize through programmatic advertising, TCF compliance is a practical necessity. Major demand-side platforms, supply-side platforms, and ad exchanges require TCF consent signals before they will bid on inventory from EU and UK audiences. Without a TCF-compliant consent management platform, publishers lose access to the majority of programmatic demand, directly impacting ad revenue.
Google Ad Manager, Amazon Publisher Services, Xandr, and other major platforms all require TCF v2.2 consent strings. Publishers that cannot provide these signals see their inventory treated as non-consented, which typically results in 50 to 70 percent lower CPMs or outright bid suppression.
Advertiser Campaign Reach
Advertisers targeting EU and UK audiences through programmatic channels depend on TCF consent signals to reach consented users at scale. Without TCF integration on the publisher side, advertiser campaigns lose access to significant portions of their target audience, reducing campaign effectiveness and increasing cost per acquisition.
Regulatory Alignment
While the TCF is an industry framework rather than a law, it was designed to operationalize the consent requirements of the GDPR and ePrivacy Directive. European data protection authorities, including the Belgian DPA and the French CNIL, have scrutinized the framework and provided guidance that informed the v2.2 update. Implementing TCF demonstrates a good-faith effort to comply with EU privacy requirements in the advertising context.
How It Works
Purposes and Special Features
The TCF defines a set of standardized purposes for data processing in digital advertising. These include storing and accessing information on a device, using limited data to select advertising, creating profiles for personalized advertising, measuring advertising performance, and developing and improving products. Each purpose has a specific legal basis, either consent or legitimate interest, and vendors declare which purposes they rely on.
Special features, such as using precise geolocation data or actively scanning device characteristics for identification, require explicit consent and cannot be processed under legitimate interest.
The Consent String
When a user makes choices in a TCF-compliant consent banner, those choices are encoded into a Transparency and Consent String, sometimes called a TC String. This compact, base64-encoded string contains the user's consent and legitimate interest preferences for each purpose and vendor. The string is stored in a cookie and made available through the CMP API, which ad tech scripts query to determine whether they have permission to process data.
The CMP API
TCF-registered consent management platforms expose a JavaScript API (__tcfapi) that vendors call to retrieve the current consent state. This API allows vendors to check whether the user has consented to their specific purposes before processing any data. The API supports callbacks for real-time consent updates, so vendors can respond immediately when a user changes their preferences.
Apidly's TCF Integration
Certified CMP
Apidly is a registered Consent Management Platform under the IAB TCF v2.2 framework. This means the platform has been reviewed and approved to participate in the TCF ecosystem, and its consent collection interface meets the framework's transparency and functionality requirements.
Global Vendor List Management
The Global Vendor List is updated regularly as vendors join, leave, or modify their purpose declarations. Apidly automatically syncs with the latest GVL version, ensuring that your consent banner always reflects the current set of vendors and purposes. When a vendor you use updates their purpose declarations, Apidly flags the change and adjusts your consent interface accordingly.
Consent Interface
Apidly's TCF consent banner presents users with clear, layered information about data processing purposes and vendors. The first layer provides a concise summary with accept and reject buttons. The second layer allows users to make granular choices per purpose and per vendor. The interface meets TCF v2.2 requirements for equal prominence of accept and reject options and clear disclosure of legitimate interest processing.
Publisher Controls
Publishers can configure which vendors appear in their consent interface based on the ad tech partners they actually use, rather than presenting the entire Global Vendor List. Apidly supports publisher restrictions that limit specific vendors to specific purposes, and allows publishers to establish legal basis restrictions where they require consent for purposes that a vendor would otherwise process under legitimate interest.
Consent String Distribution
Once a user makes their choices, Apidly generates the TC String and makes it available through the standard CMP API. The string is also stored server-side in Apidly's consent records for audit purposes. All ad tech scripts on the page can query the API to determine their permissions before processing any data.
Reporting and Analytics
Apidly provides detailed TCF consent analytics, including consent rates by purpose and vendor, opt-in versus opt-out trends over time, geographic breakdowns, and the impact of consent rates on programmatic revenue. These reports help publishers optimize their consent interface and understand the relationship between consent collection and ad monetization.
Setup Guide
Step 1: Register for TCF
If your organization is not yet a participant in the IAB TCF, Apidly guides you through the registration process. Publishers register as a TCF participant, and Apidly serves as your registered CMP.
Step 2: Configure Your Vendor List
In the Apidly dashboard, select the ad tech vendors you work with from the Global Vendor List. Apidly pre-populates common vendor selections based on the scripts detected on your site. Review the purposes each vendor requires and configure any publisher restrictions.
Step 3: Customize the Consent Interface
Design your TCF consent banner using Apidly's visual editor. Choose colors, typography, and layout that match your site's design while meeting TCF v2.2 requirements for clarity and equal prominence. Preview the banner in both first-layer and second-layer views before publishing.
Step 4: Deploy and Verify
Add the Apidly script to your site if it is not already present. The TCF consent interface activates automatically for visitors in jurisdictions where TCF applies. Use the IAB's CMP Validator tool and Apidly's built-in diagnostics to confirm that the TC String is being generated and distributed correctly.
Step 5: Monitor and Optimize
Review your TCF consent analytics in the Apidly dashboard to track consent rates and their impact on programmatic revenue. Experiment with banner copy, layout, and timing to find the optimal balance between consent rates and user experience.