Children travel free until their fifth birthday. After that they pay child fares, but the level of discount varies depending where you are in the UK. The age from which full fares apply also varies according to where you are. For your local area details please call customer services on 0344 800 44 11 between 8am and 6pm Monday to Friday.
Very useful information from Arriva.
RE: Arriva North East: Latest News & Discussion - April 2015