As soon as both parents are not living under the same roof with the child, child support starts accruing. However, when you and the other parent are getting along, sharing custody, taking care of the child’s basic needs, and jointly making decisions about the child, there is no urgency to go to court to get a formal calculation. It is your right but many parents do not start exercising this right until there is a breakdown in the relationship between themselves and the other parent.