EU AI Act glossary · Operator roles· Art. 25
Substantial modification
A substantial modification is a change to a high-risk AI system — to its intended purpose or one affecting its compliance — that was not foreseen in the original conformity assessment, triggering a fresh assessment.
Under Article 25, an operator that substantially modifies a high-risk system, or repurposes it into a high-risk use, is treated as the provider for that system and inherits the full provider obligations.
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