AI Work FluencyEU AI Act glossary

Grandfathering Grandfathering (régi rendszerek átmenete)

Verified: 2026-08-04 · Legal source: 111. cikk

Short definition

Grandfathering refers to the rule under which the Regulation applies to AI systems already placed on the market before the application date of the high-risk block only if they undergo a substantial modification affecting their design. This protection does not extend to prohibited practices — the prohibition applies to those immediately, with no grace period.

The rule is set out in Article 111(1)–(4). Its practical significance is that an already-operating, previously deployed system does not have to be automatically brought into retroactive compliance with the high-risk requirements — only if the provider carries out a substantial modification affecting its design. This gives important protection for continuity, but also hides a trap: many companies wrongly believe this protection also extends to prohibited practices, whereas Article 111 expressly excludes them from the transitional rules — a system placed on the market in 2024 that performs workplace emotion recognition has been unlawful since 2 February 2025, regardless of it being a legacy system. For large-scale systems used by public authorities, Article 111(2) grants a further, narrower transition until 2 August 2030.

Why this matters for an EU SME

For an old, legacy AI system, many assume "it's already deployed, nothing to worry about" — for prohibited practices this is a dangerously false assumption, since grandfathering does not extend to them.

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Related terms

Related questions in the knowledge base (Hungarian)

This page is general information, not legal advice. It does not substitute for a legal assessment of a specific case and does not create a retainer or attorney-client relationship. The legal status was verified on 4 August 2026 against primary sources; where the law or regulatory practice is uncertain, this is flagged separately.