Thank you for your response.
My apologies for my delay in responding to you as I have had quite a busy day.
If you truly have an 'equal' shared care arrangement where the time spent caring from your son is exactly equal between you neither of you should make a cliam to the CMS for maintenance.
The Legal basis for this is as follows:
Regulation 50 (2) Child Support Maintenance Calculation regulations 2012 states:
(2) For the purposes of this special case, the person mentioned in paragraph (1)(b) is to be treated as the non-resident parent if, and only if, that person provides day to day care to a lesser extent than the applicant.
You would need to evidence exactly equal day to day care. This involves the overall care arrangements for the child being shared equally and not just where they stay overnight.
You should diarise your position in relation to the care that your provide for your son if you consider that this is the case. The mother might dispute the position and you will need try and evidence your position.
If it is not a 'true shared care arrangement' then maintenance is still payable to mother although a reduction would be made in light with the number of nights that your son spent with you - see this guide for the banding of nights:
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