CLAIM-2026-08-12-06

AI Act Article 3(23) defines 'substantial modification' as a change to an AI system after its placing on the market or putting into service which is not foreseen or planned in the initial conformity assessment carried out by the provider and as a result of which the compliance of the AI system with the requirements set out in Chapter III, Section 2 is affected or results in a modification to the intended purpose for which the AI system has been assessed.

Why it matters

The definition turns on foresight at assessment time, not on the size of the change. An undetermined change is substantial by definition however small it is.

Sources

• euaiactexpl2026definitio