22nd December 2023|In Latest News, Children

How Child Maintenance is Calculated – 3 Steps

Understanding how child maintenance is determined is a frequent query at Blanchards, with significant implications for both parents’ finances.

Navigating the complexities of CMS (Child Maintenance Services) and child maintenance calculators might seem overwhelming, but due to the formulaic nature of the process, you just provide your information and the system calculates the rest.

Here’s a breakdown of what the Child Maintenance Service considers when setting the weekly child maintenance amount.

1. Parental Income

The CMS assesses the income of the parent responsible for payments by reviewing their annual gross income data from HM Revenue and Customs (HMRC), excluding any government benefits, tax credits, student grants, and loans. Adjustments are made for factors like pension contributions, other dependents, or financial assets. The final figure is then converted into a weekly payable amount.

Note: The income of the primary caregiving parent is not considered in this calculation.

2.  Child Maintenance Rates

The gross weekly income of the paying parent determines which of the five set rates is applicable.


Gross weekly income Rate Weekly amount
Unknown or not provided Default £38 for 1 child, £51 for 2 children, £64 for 3 or more
Below £7 Nil £0
£7 to £100, or if the paying parent gets benefits Flat £7
£100.01 to £199.99 £100.01 to £199.99 Calculated using a formula
£200 to £3,000 Basic Calculated using a formula


Note: For weekly incomes exceeding £3,000, the other parent can seek additional maintenance through court.

3. Additional Dependents & Shared Care Arrangements

The CMS accounts for other children the paying parent supports, impacting the weekly income by a set percentage. For instance:

  • For one additional child, the income reduces by 11%.
  • For two additional children, it reduces by 14%.
  • For three or more, it reduces by 16%.

Shared care is also factored in, with deductions made based on the average number of overnight stays per week.

While CMS’s processes have been streamlined over time for simplicity and quicker outcomes, the strict nature of these calculations can still present challenges in certain scenarios, which we will explore in our next post.

Can we help you? Please call us on 0333 344 6302 or contact us through our enquiry form. All initial enquiries are free and without obligation.

"*" indicates required fields