CRA pays all of them, on family net income from the base year (as for the Canada Child Benefit).
Child Tax Benefit and Working Income Supplement
$250 a year for each child under 18, less 5% (2.5% with one child) of family income over $20,000. A family with children also gets up to $250 a year as a working income supplement: 4% of family earnings over $3,750, less 5% of family income over $20,921. Both are paid monthly.[1]
School Supplement
$100 each July for each child aged 5 to 17 on 1 July, when family income is $20,000 or less.[2]
HST credit
$300 for the person, $300 for a spouse (or a single parent's first child) and $100 for each other child, less 2% of family income over $35,000, paid a quarter at a time in January, April, July and October.[3]
What it does not do
The child tax benefit for a child in shared custody is not modelled: the plan stops with a reason. See income tax in New Brunswick.