When is the exam time for preliminary test?

Each country may determine its own preliminary test schedule. Holding it around March is perfectly acceptable.

Each team consists of 4 contestants and 1 team leader.
Additional participants may register separately as observers.

ICO is fundamentally a solo (individual) competition.
Since ICO 2025, each contestant is required to independently complete all tracks, unlike many university contests where teams are divided by specialisation.

Contestants must be under 20 years old on the competition day.