Toilet Training Myth: Children complete toilet training by age 3 Yeah-no, a child doesn't really grasp what being 3 means so don't expect thier bladder to understand the expectations either. There are ways to encourage toilet training, however if the definition of 'toilet trained' includes night time, then no. Most children will not be completely trained by 3 & some children will (occasionly) wet up until age 9. #thenappyshop #thenappyshoponline #thenappyshopaus #toddlerunderwear #toddlerundies