How the Child Maintenance Service works out child maintenance

The Child Maintenance Service usually follows 6 steps to work out the weekly amount of child maintenance.

This guide is also available in Welsh (Cymraeg).

The child maintenance calculator shows you what the government is likely to work out for you.

How child maintenance is worked out

Step 1 - working out income

The Child Maintenance Service will find out the paying parent’s yearly gross income from information supplied by HM Revenue and Customs (HMRC).

They’ll also check if the paying parent is getting benefits (tax credits, student grants and loans don’t count as income).

The ‘paying parent’ does not have main day-to-day care of the child. The ‘receiving parent’ has main day-to-day care of the child.

Step 2 - looking at things that affect income

The Child Maintenance Service will check for things that could change the gross income amount (for example, pension payments or other children they support).

You can also ask for extra income, assets or expenses to be taken into account.

They’ll convert the yearly gross income into a weekly figure.

Step 3 - child maintenance rates

One of 5 rates will be applied, based on the gross weekly income of the paying parent.

Gross weekly income Rate Weekly amount
Unknown or not provided Default £38 for 1 child, £51 for 2 children, £61 for 3 or more children
Below £7 Nil £0
£7 to £100, or if the paying parent gets benefits Flat £7
£100.01 to £199.99 Reduced Calculated using a formula
£200 to £3,000 Basic Calculated using a formula

If the paying parent’s gross weekly income is more than £3,000, the receiving parent can apply to the courts for extra child maintenance.

Step 4 - other children

The Child Maintenance Service will take into account the number of children the paying parent has to pay child maintenance for. This includes any other children living with them and any arrangements that have been made directly for other children.

Step 5 - weekly amount of child maintenance

Using information from the first 4 steps, the Child Maintenance Service decides the weekly child maintenance amount.

Step 6 - shared care

This is when a paying parent’s child stays overnight with them.

In these cases, the Child Maintenance Service makes a deduction to the weekly child maintenance amount based on the average number of ‘shared care’ nights a week.

Asking for other income and expenses to be included

You can ask the Child Maintenance Service to take other income and expenses into account when working out child maintenance payments. This is called ‘applying for a variation’.

You can ask for a variation when you apply for child maintenance or after your child maintenance has been worked out.

After you apply for a variation, it can take up to 3 months for your Child Maintenance payment amount to change.

Income and assets

Both the paying and receiving parent can ask for the following types of income and assets to be taken into account:

  • rental income over £2,500 a year
  • interest and dividends from savings and investments over £2,500 a year
  • gross earnings or pension of at least £100 a week - if the paying parent gets benefits and qualifies to pay the ‘flat rate’ of child maintenance
  • any income the paying parent may be diverting so that it is not included in the calculation (for example, giving it to someone else or choosing to have a company car instead of a higher salary)
  • assets like shares, stocks, gold or money worth more than £31,250


If you’re the paying parent, you can ask for the following types of expenses to be taken into account:

  • costs of keeping in regular contact with a child you pay maintenance for (for example, fuel to travel between your home and the child’s)
  • costs of supporting a child with a disability or long term illness who lives with you
  • repaying debts from a previous relationship
  • boarding part of boarding school fees for a child you pay maintenance for
  • mortgage, loan or insurance payments for the home you used to share with the receiving parent - if the receiving parent and your child still live there

Each type of expense must be more than £10 a week. The costs of supporting a child with a disability or long-term illness can be less.

You cannot ask for expenses to be taken into account if your gross income is less than £7 a week.

Contact the Child Maintenance Service to apply for a variation.

When payments can change

The amount you pay or receive in child maintenance can change when:

  • your case is reviewed each year
  • you or the other parent applies for a variation
  • the paying parent has a change of circumstances that affects their income or expenses, for example if the child stays overnight with them more often - you must report a change as soon as it happens