Identity Solutions (AdTech)
As third-party cookies deprecate, identity solutions like UID2, ID5, and RampID have emerged as alternatives. These solutions carry their own privacy requirements and regulatory scrutiny.
By Sergio Maldonado Elvira, Attorney, State Bar of California · FIP, CIPP/US, CIPP/E, CIPT
Published · Last reviewed
Key points
- →Evaluate UID2, ID5, and alternatives
- →Ensure valid consent for ID creation
- →Navigate cross-device tracking rules
- →Prepare for evolving browser restrictions
Identity solution landscape
Alternative identity solutions fall into categories: deterministic (based on authenticated data like email), probabilistic (statistical matching across signals), contextual (not user-based), and hybrid approaches. Each has different accuracy, scale, privacy, and compliance characteristics. No solution perfectly replaces third-party cookies—you'll likely need a portfolio approach.
Consent requirements for ID creation
Creating identity tokens from user data requires valid consent or other lawful basis. Under GDPR, identity solutions for advertising typically require consent. The consent must be specific to the identity solution—blanket 'personalization' consent may not suffice. Ensure your consent flows explicitly mention identity resolution and cross-site tracking purposes.
Cross-device and cross-site tracking
Identity solutions enabling cross-device tracking face heightened scrutiny. Regulators view such tracking as particularly privacy-invasive. GDPR requires transparency about cross-device linking. CCPA categorizes cross-context behavioral advertising as 'sharing' requiring opt-out mechanisms. The UK ICO has specifically examined adtech identity solutions.
Future-proofing identity strategy
Browser restrictions continue evolving—Privacy Sandbox, Safari ITP, Firefox ETP. Regulatory frameworks increasingly target identity solutions. Build flexibility: invest in first-party data strategies, test multiple identity providers, implement server-side approaches, and monitor regulatory developments. Don't bet everything on a single solution.
Related reading
This guide is general information, not legal advice. Reading it does not create an attorney-client relationship. The law is stated as of January 28, 2026.
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