No you can agree a figure between you, unless you as the parent with care of the children receives certain means-tested benefits, in which case you are obliged by the DSS to apply for an assessment by the Child Support Agency. If that you refuse to make an application, you may be penalised by having your benefit payments reduced by a draconian amount - 40% - for an unlimited time.
Other single parents who do not receive benefits may apply to the CSA for an assessment if they wish to, as long as there is no Court Order in force regulating payments. They may however prefer to agree a figure for child maintenance, bearing the Child Support Act calculation in mind.
The new Child Support legislation sets out a very simple basic formula to calculate the level of child maintenance payable by the non-resident parent. Unlike the original scheme, this is based solely on the net income of the non-resident parent and the number of natural children he or she has not living in his household.
The court still retains its powers to make orders for the payment of school fees, maintenance for step children or disabled children and for those in further education and in certain other specific situations. It can also order that capital sums be paid for children, or property be made available for them, in certain circumstances.
The Child Support legislation governs the level of child maintenance that should be paid by a natural parent (not a step-parent, even if he or she has in the past assumed financial responsibility for the child) who is not resident in the child's household to the parent with care.
It does not cover:
where the absent parent is resident outside the UK;
if the parent with care is resident outside the UK;
if the child is resident outside the UK.
It covers natural children up to the age of 17, or 19 if they are in certain types of full time education.
The Child Support Agency will usually only work out and collect child maintenance if someone applies for it. The Child Support Agency can accept applications from parents with care, non-resident parents, children who are aged 12 or over in Scotland and other people caring for qualifying children if all the people involved live in the UK. Special rules apply if:
the parent with care is on Income Support or income-based Jobseeker's Allowance;
there are already maintenance arrangements for the qualifying child; or