IAB Europe Transparency & Consent Framework — TCF v2.3 (2026)

TCF v2.3 launched in April 2025, superseding TCF v2.2 (effective April 2023). The headline change is a mandatory technical mechanism — repurposing the "Disclosed Vendors" section of the TC string — that lets CMPs and vendors verify a vendor was actually disclosed to the user, closing a legitimate-interest disclosure gap that existed under 2.2.

Enforcement timeline. TCF participants had until February 28, 2026 to migrate to v2.3. As of March 1, 2026, TC strings generated under TCF 2.2 or earlier became technically invalid within the Framework — CMPs and publishers still emitting 2.2-only strings are out of compliance with the Framework's own technical validation, which independent commentary (as of mid-2026) reports has already begun affecting programmatic demand access for laggard implementations.

Relevance to constraint.iab-tcf-2-2-eu-programmatic-advertising. That node documents TCF 2.2 as the "operative consent standard... as of April 2023" without noting that 2.2 has since been superseded and its TC strings are now invalid. This is a material update, not a body refinement — see drafted candidate in evolution-log/2026-08-16/web-refresh.md.