Most social welfare payments include an increase for any children that you have who are under 18.  Some payments include an increase until a child turns 22 if they are still in full-time education.

If you do not live with your child, you may still be able to claim an increase if you are paying maintenance, and as long as nobody else is claiming for that child.  If this is the case and you are working at least 19 hours, you may be able to claim Family Income Supplement.

If your child requires full-time care and attention, or requires substantially more care than a child of their age would normally require, you may be able to claim a Carer's Allowance payment, a Domiciliary Care Allowance, or both.

If you are looking after a child whose parents have died or who are unable to look after the child, you may be able to claim a Guardian's Payment.

Child Benefit is a separate payment and is paid until a child's 18th birthday.  This payment cannot continue after this time even if the child is still in full-time education.