my advice is to go back to court and get the eow contact arranged so you also get to spend some quality time with your son. i would also get the child maintenance order too, even if she doesn't pay it it will at least be on record that she refuses to support her son financially. you do not 'owe' her any money for anything she spends on her son during her contact time. She would only get a reduction in the amount of CM she pays if she were paying it in the first place.
here's what the guidelines say, Point 3 is more relevant to you, (just substitute 'father' for 'mother' - they don't seem to have realised that fathers can be the main carer too) on www.childsupportsolutions.co.uk/pwc-calculation.htm
New Style Calculation (After 3rd March 2003)
All applications commenced after the 3rd March 2003 are dealt with under the new child support scheme. This scheme is much simpler than the old calculation method but is still by no means easy.
Under the new scheme child support payable by the father is calculated as follows:-
Determine the father's net income. This is gross pay, less Tax, NI and all pension scheme contributions.
- Determine how many children live with the father. Net income is then reduced by 15% for one child living with the father, 20% for two, 25% for three or more.
- Apply the basic child support calculation. 15% of net pay (after deduction for any children living with the father) for one child, 20% for two, 25% for three or more.
- Calculate and reduce by any amount of shared care. Shared care is calculated by determining the number of nights your child stays with their father. If a child stays with their father below 52 nights per annum (1 night per week) the amount of child support is unchanged. If the amount of contact is between 52 and 103 nights per annum (1 night per week) child support reduced by one-seventh. If the child stays with the father between 104 and 155 nights per annum the amount of child support is reduced by two-sevenths. If the contact amounts to between 156 and 174 nights per annum (three nights per week) the child support is reduced by three-sevenths. Contact in excess of 175 nights per annum reduces the child support figure by 50% since in effect the child spends as much time with the father as it does with the parent with care. Furthermore, in those cases an extra sum of £7.00 for each of your children that stays overnight with their father in excess of 175 nights per annum is deducted.
You should note that the new system does not include any enquiry into your earnings or indeed the fathers partners earnings. Furthermore all children that live with the father are taken into account, even if he is not the natural father of those children and even if their natural father is paying child support.
In most cases it would be simple, a father living on his own would pay 15% for one child, 20% for two, 25% if he has three or more. If he has more than one child by more than one mother with whom he does not live then the amount payable is determined by the percentage and divided equally between the mothers concerned. For instance a father earning £300.00 per week with three children, two by mother (A) and one by mother (B) would pay £75.00 per week. Mother (A) having two children would receive £50.00 of that, mother (B) would receive £25.00.