GDPR regulates the processing of personal data. The AI Act regulates the safety and reliability of AI systems, whether or not they process personal data. An AI system that only processes industrial sensor data with no identifiable person involved can be subject to the AI Act without GDPR ever coming into play. And the reverse: personal data processing with no AI system involved never triggers the AI Act. The confusion comes from the fact that, in practice, most high-risk AI systems do process personal data — but it's not a universal rule.
Where they genuinely overlap
| Area | GDPR | AI Act |
|---|---|---|
| Data quality | Art. 5 — accuracy and minimization | Art. 10 — relevance, representativeness, absence of errors |
| Impact assessment | DPIA (Art. 35) for high-risk processing | Conformity assessment for high-risk systems |
| Transparency | Right to information (Arts. 13-14) | Art. 50 transparency obligation |
| Automated decisions | Art. 22 — right not to be subject to automated decisions | Human oversight requirement (Art. 14) |
If you've already built a solid data quality management foundation, most of the quality work required by both regulations is already done — the difference lies in the specific documentation each one requires, not in the underlying technical work.
Where they DON'T overlap (and you have to comply with each separately)
- Legal basis for processing: the AI Act doesn't replace the need for a valid GDPR legal basis (consent, legitimate interest, legal obligation...) for any personal data used in the system.
- Risk classification: a processing activity not requiring a DPIA under GDPR doesn't mean the AI system isn't high-risk under the AI Act's Annex III — they're different criteria.
- Penalties: calculated and applied independently, by different authorities (the AEPD for GDPR, AESIA for the AI Act) — complying with one doesn't reduce exposure to the other.
The AEPD's guidance on agentic AI is a good example of how Spain's data protection authority is already interpreting these overlaps in practice — worth reading if your system makes decisions autonomously.