Google will require IAB TCF v2.3 for all newly generated TC strings starting February 28, 2026. This article explains what changed, why the disclosedVendors segment matters, and how publishers can prepare to avoid Limited Ads and consent signal disruption.
TCF v2.3 Deadline: What Publishers Must Do Before February 28, 2026
TCF v2.3 Deadline: February 28, 2026 (Google Official Transition Timeline)
The IAB Europe Transparency & Consent Framework (TCF) v2.3 is now officially live, and Google has confirmed that it will become mandatory for all newly generated TC strings on February 28, 2026.
If your publishing business operates in the EEA, UK, or Switzerland and relies on Google Ad Manager, AdSense, or AdMob, this deadline directly affects your consent signals and ad monetization.
Here’s exactly what changes, what happens if you don’t migrate, and how to prepare during the transition window.
What is TCF v2.3?
The IAB Transparency & Consent Framework (TCF) is the standardized protocol used across Europe to communicate user consent signals between publishers, advertisers, and ad tech vendors.
A TCF consent decision is encoded into a TC string, which ad partners use to determine:
- Whether personalized ads can be served
- Whether vendors can process data
- Whether Legitimate Interest applies
- Whether Special Purposes are disclosed
TCF v2.3 is the latest version of this framework.
What changed in TCF v2.3?
The most significant update in TCF v2.3 is the introduction of a mandatory “disclosedVendors” segment in the TC string.
The disclosedVendors segment (key change)
The disclosedVendors segment provides a binary indicator (1 or 0) confirming whether a vendor was actually disclosed in the Consent Management Platform (CMP) interface.
Why this matters
Previous framework versions created ambiguity around vendor disclosure. Vendors could rely on Legitimate Interest for Special Purposes without clear proof that they were displayed to users.
TCF v2.3 removes this ambiguity by requiring explicit signaling that a vendor was disclosed in the UI.
In short:
TCF v2.3 strengthens transparency signaling between publishers and ad partners.
Official TCF v2.3 Timeline
Google has outlined a structured transition period:
Phase | Date | What it means |
|---|---|---|
Support live | Now | Google systems accept TCF v2.3 strings |
Transition period | Now – Feb 28, 2026 | TCF v2.3 treated like v2.2 for processing |
Final deadline | February 28, 2026 | New TCF v2.2 strings no longer supported |
Post-deadline | March 1, 2026 | New non-compliant strings may default to Limited Ads |
During the transition window, Google will not invalidate v2.3 strings lacking disclosedVendors. This allows safe deployment and testing.
After February 28, 2026, TCF v2.3 is mandatory for newly generated TC strings.
What happens if you don’t migrate?
After the deadline:
- New TCF v2.2 strings will not be supported
- TC strings missing mandatory segments may be deemed invalid
- Affected ad requests may default to Limited Ads
- Personalization and frequency capping may be restricted
- Monetization performance may be impacted
For publishers relying on programmatic revenue, consent signal integrity directly affects ad eligibility and fill performance.
This is not just a framework update; it is part of the advertising infrastructure.
TCF v2.2 vs TCF v2.3: What’s the difference?
Feature | TCF v2.2 | TCF v2.3 |
|---|---|---|
Vendor disclosure proof | Not mandatory | Mandatory disclosedVendors segment |
Signaling ambiguity | Possible | Reduced |
Google validation post-2026 | Unsupported for new strings | Required |
Revenue impact risk | Low (before 2026) | Required for monetization continuity |
Why the transition window matters
Google’s transition period gives publishers time to:
- Deploy v2.3 strings
- Validate vendor configurations
- Test ad delivery outcomes
- Confirm CMP certification
- Review Global Vendor List alignment
Waiting until early 2026 increases operational risk and reduces testing time.
Consent migrations typically involve coordination across:
- Legal teams
- Ad operations
- Engineering
- Vendor partners
- CMP providers
Early migration reduces disruption.
TCF v2.3 is part of a bigger shift
The move to TCF v2.3 reflects a broader trend:
Consent frameworks are now revenue infrastructure.
Publishers are navigating:
- Privacy-first regulatory enforcement
- Consent Mode alignment
- Increased vendor accountability
- Signal validation
- Monetization modeling changes
Consent signaling is no longer just compliance; it influences ad eligibility.
How to prepare for the TCF v2.3 deadline
1. Verify your current TC string version
Confirm whether your CMP is generating TCF v2.2 or TCF v2.3 strings. This can typically be validated through your CMP dashboard or by inspecting live TC strings in your ad requests.
2. Confirm CMP certification
If you use Google Ad Manager, AdSense, or AdMob, ensure your CMP is Google-certified for TCF v2.3. Certification confirms compatibility with Google’s consent validation logic after February 2026.
3. Enable the disclosedVendors segment
Verify that your CMP configuration properly encodes the mandatory disclosedVendors segment in newly generated TC strings. During the transition period this may not trigger validation errors, but it will be required after the deadline.
4. Review your vendor list
Audit your partners against the TCF v2.3 Global Vendor List (GVL). Vendors not registered under the updated framework may be unable to process consent signals properly.
5. Test ad requests
Monitor Google Ad Manager delivery logs and consent signals in test environments. Validate that TC strings are accepted and not defaulting to Limited Ads under different user scenarios.
6. Plan regional deployment
If you operate across multiple EU jurisdictions, ensure consistent consent handling across domains and subdomains. Align language, vendor disclosures, and configuration logic to avoid regional inconsistencies.
7. Document Your Migration Timeline
Create an internal migration plan with clear ownership across legal, ad operations, and engineering teams to avoid last-minute deployment pressure in early 2026.
How Clym supports TCF v2.3 migration
Clym’s Consent Management solution supports structured TCF v2.3 string generation with flexible regional configuration options.
Publishers can:
- Generate compliant v2.3 TC strings
- Customize vendor disclosure behavior
- Configure consent by jurisdiction
- Maintain existing consent flows
- Manage updates from a centralized dashboard
This enables publishers to migrate during the transition window without rebuilding their consent infrastructure.
Learn more: https://www.clym.io/solutions/consent-management/iab-tcf
Final takeaway
The February 28, 2026 deadline is a technical requirement, but its implications are operational.
Publishers that migrate early can test, validate, and optimize consent signaling before enforcement begins.
Consent frameworks are evolving, and infrastructure readiness is now part of the monetization strategy.
Frequently asked questions
Yes. TCF v2.3 becomes mandatory for all newly generated TC strings starting February 28, 2026.
It is a required binary segment in the TC string that confirms whether a vendor was displayed in the CMP interface.
Generally, re-consent is not required solely due to this framework update.
New TCF v2.2 strings will no longer be supported. Strings created before the deadline may remain valid.
Limited Ads are ads served without personalized cookies or full targeting capabilities, which may impact monetization performance.
TCF v2.3 operates alongside consent signaling used in Google ecosystems. Alignment between frameworks supports signal consistency.
The requirement primarily applies to publishers monetizing traffic in the EEA, UK, and Switzerland.
Adam is the Head of Digital Marketing at Clym, where he leverages his diverse expertise in marketing to support businesses with their compliance needs and drive awareness about data privacy and web accessibility. As one of the company’s original team members, Adam has been instrumental in shaping its journey from the very beginning. When he’s not diving into marketing strategies, Adam can be found cheering on his favorite sports teams or enjoying fishing.
Find out more about Adam