From what age and onwards do children have to pay for a ticket?

Only children up to 5 years old are allowed entry without a ticket (without a guaranteed seat) to Olympiacos games.
For the entry of children over 5 years old, a ticket must be issued or the child must possess a season ticket in their name.
Additionally, the companion of the child must have an official document proving the date of birth of the child(ren) they are accompanying.
Failure to follow the above instructions will result in denied entry.