Child Maintenance Calculator

When parents separate, child maintenance is the money the parent who doesn't have day-to-day care pays towards their child's everyday costs. Getting the amount right matters to both parents, and knowing how it's calculated helps you agree a fair figure or know what to expect from the Child Maintenance Service.

This guide explains how the statutory formula works in England, Scotland and Wales. To estimate a payment, use the child maintenance calculator.

Who pays child maintenance?

The paying parent is usually the parent who doesn't have main day-to-day care of the child. The receiving parent is the one who does. Maintenance is generally due for children under 16, or under 20 if they're in approved education or training.

Two ways to arrange it

A family-based arrangement

Parents can agree the amount and how it's paid between themselves, without involving the government. This is flexible and has no fees, and you can use the official formula as a starting point. It isn't legally binding, though.

The Child Maintenance Service

If you can't agree, either parent can apply to the Child Maintenance Service (CMS). It uses a set formula based mainly on the paying parent's income and can enforce payments if needed.

How the formula works

The CMS starts with the paying parent's gross weekly income, usually taken from HMRC records. Gross means before tax and National Insurance, though some pension contributions are deducted. It then applies a rate depending on which band that income falls in:

Income above £3,000 a week isn't included in the CMS calculation.

Basic rate percentages

For most paying parents, the basic rate applies. The percentage depends on how many children the maintenance is for:

Other children the paying parent supports

If the paying parent also supports other children living with them, their income is reduced before the percentage is applied: by 11% for one other child, 14% for two and 16% for three or more.

A worked example

Alex earns £30,000 a year and pays maintenance for one child, with no other children at home and no shared care.

• Gross weekly income: £30,000 ÷ 52 = about £576.92
• Basic rate for one child: 12%
• Weekly maintenance: about £69.23, or roughly £300 a month

You can see how other circumstances change this in the child maintenance calculator.

Shared care reduces the amount

If the child regularly stays overnight with the paying parent, the amount is reduced to reflect the costs they already cover:

The paying parent normally still pays at least £7 a week. For parents on the flat rate, shared care of 52 nights or more can reduce the amount to nothing.

Direct Pay or Collect and Pay

If you use the CMS, there are two ways the money can be paid:

• Direct Pay: the CMS works out the amount and the paying parent pays the receiving parent directly. There are no collection fees.
• Collect and Pay: the CMS collects the money from the paying parent and passes it on. The paying parent pays an extra 20% on top, and 4% is deducted from what the receiving parent gets.

What if circumstances change?

Child maintenance is reviewed each year, and you should report changes such as a significant change in income, a change in the number of children, or a change in overnight stays. A change in income of 25% or more usually triggers a recalculation.

Northern Ireland

Northern Ireland has its own Child Maintenance Service with very similar rules. The figures in this guide apply to England, Scotland and Wales.

Getting help to agree an arrangement

If you'd like to agree an arrangement between yourselves but find it difficult, free support is available. Family mediation services can help separated parents agree arrangements for children and money, and GOV.UK has guidance on making a family-based arrangement, including a form to record what you agree. Recording the details clearly, such as the amount, when it's paid and how often it's reviewed, can help avoid misunderstandings later.