Child Maintenance UK: How Much You Pay or Get and How the CMS Works It Out

When parents separate and cannot agree child maintenance privately, the Child Maintenance Service (CMS) in England, Wales and Scotland works it out using a statutory formula based on the paying parent's gross weekly income, taken directly from HMRC records; how much that comes to depends on that income, the number of qualifying children, any overnight shared care and any other children the paying parent supports.

What Is Child Maintenance and Who Pays It?

Child maintenance is regular financial support paid by a parent who does not have main day-to-day care of a child to the parent (or other person) who does, to help with the child's everyday living costs. It applies whether or not the parents were ever married, and it is separate from any wider financial settlement on divorce. Parents in England, Wales and Scotland who cannot agree maintenance privately can use the Child Maintenance Service, a government body that assesses and, if needed, enforces payment. The CMS is not a court, and it is not the same as spousal maintenance. Parents remain free to agree their own arrangement without involving the CMS, but if they cannot agree, or an arrangement breaks down, either parent (or a grandparent or guardian with main day-to-day care, or in Scotland a child aged 12 or over) can apply for a statutory CMS calculation, which is legally binding once made. The CMS cannot be used while a court order for child maintenance (usually a consent order) is less than a year old, or, in Scotland, while a maintenance agreement registered in the Books of Council and Session or the sheriff court books is less than a year old.

How the CMS Works Out Gross Weekly Income

The CMS calculation starts from the paying parent's gross weekly income, meaning income before tax and National Insurance are deducted, but after deducting pension contributions (contributions an employer deducts from pay before tax are already reflected in the HMRC figure; other contributions, such as payments made directly to a private pension provider, are deducted if the paying parent asks the CMS and provides the details). This figure normally comes directly from HMRC's records for the most recent tax year, rather than payslips supplied by either parent, which is intended to reduce disputes over the starting figure. The CMS then applies one of five rates to that gross weekly income to reach a base weekly maintenance amount, before any further adjustment for other children in the paying parent's household or for shared overnight care. Only after all of those steps is the final weekly liability set.

In practice the calculation runs in a fixed order: work out gross weekly income, reduce it for any relevant other children, apply the rate band and percentage for the number of qualifying children, then reduce the result for any overnight shared care.

The Five CMS Rate Bands

Which of the five rates applies depends entirely on the paying parent's gross weekly income, as shown below.

Income above £3,000 a week is disregarded entirely by this formula. A receiving parent who believes the paying parent's true resources are higher can apply to a court for an additional top-up order, but that sits outside the CMS calculation.

Basic and Basic Plus Rates by Number of Children

At the Basic rate (gross weekly income £200 to £800), the percentage charged rises with the number of qualifying children: 12% for one child, 16% for two children, and 19% for three or more. At Basic Plus (the slice of income between £800.01 and £3,000), a lower percentage applies to that additional slice: 9% for one child, 12% for two children, and 15% for three or more, on top of the Basic-rate amount already charged on the first £800. So a Basic Plus liability is calculated in two parts and then added together, not as a single percentage of the whole income.

The Reduced Rate

Between £100.01 and £199.99 of gross weekly income, the paying parent owes a flat £7 plus a percentage of the income above £100: 17% for one child, 25% for two children, or 31% for three or more, where the paying parent has no other relevant children. Where the paying parent also has relevant other children, a lower percentage from a separate table in regulation 43 applies instead (for example 14.1% rather than 17% for one qualifying child and one other child); the 11%, 14% and 16% income reduction described below is not used at this band.

Other Children Living With the Paying Parent

If the paying parent (or their partner) receives Child Benefit for other children living in their household, the CMS reduces the gross weekly income figure before applying the Basic or Basic Plus rate: by 11% for one other child, 14% for two other children, or 16% for three or more other children. This reduction happens before the rate band percentage is applied, so it lowers the base figure the percentage is calculated from, not the final maintenance amount directly.

Shared Care: How Overnight Stays Reduce the Amount

Where a qualifying child stays overnight with the paying parent, the weekly maintenance for that child is reduced according to how many nights a year that happens: a deduction of one-seventh for 52 to 103 nights a year, two-sevenths for 104 to 155 nights, three-sevenths for 156 to 174 nights, and one-half for 175 nights or more, with a further £7 a week taken off for each child who stays 175 nights or more; shared care cannot take the amount below £7 a week. Where the Flat rate applies because the paying parent is on a prescribed benefit, shared care of at least 52 nights a year reduces that liability to nil; where the Flat rate applies purely because of low income, the £7 stays payable regardless of shared care.

Worked Examples: What the Formula Produces in Practice

These examples apply the rates, bands and reductions above to show how the sums work out in practice. They are illustrations of the statutory formula, not a prediction of what any specific parent will pay or receive; results are shown to the nearest penny.

Example 1: Basic rate, two children, no shared care

1. Gross weekly income is £600, which falls in the Basic rate band (£200 to £800).
2. There are 2 qualifying children, so the Basic rate percentage is 16%.
3. 16% of £600 = £96.
4. There is no overnight shared care, so no further reduction applies.
5. Weekly amount: £96.

Example 2: Basic rate, one child, with shared care

1. Gross weekly income is £600, again in the Basic rate band.
2. There is 1 qualifying child, so the Basic rate percentage is 12%.
3. 12% of £600 = £72.
4. The child stays overnight with the paying parent for 52 to 103 nights a year, which reduces the amount by one-seventh: £72 minus (£72 divided by 7, or £10.29) = £61.71.
5. Weekly amount: £61.71.

Example 3: Basic Plus, two children

1. Gross weekly income is £1,000, which is above £800, so the Basic Plus rate applies.
2. The Basic rate percentage for 2 children (16%) applies to the first £800: 16% of £800 = £128.
3. The Basic Plus percentage for 2 children (12%) applies to the remaining £200 (£1,000 minus £800): 12% of £200 = £24.
4. Add the two parts together: £128 plus £24 = £152.
5. Weekly amount: £152.

Example 4: Reduced rate, one child

1. Gross weekly income is £150, which falls in the Reduced rate band (£100.01 to £199.99).
2. The flat £7 applies first.
3. Add 17% of the income over £100: £150 minus £100 = £50, and 17% of £50 = £8.50.
4. Add the two parts: £7 plus £8.50 = £15.50.
5. Weekly amount: £15.50.

Example 5: Basic rate with a relevant other child

1. Gross weekly income is £500, in the Basic rate band, for 2 qualifying children.
2. The paying parent has 1 other child living with them (a child they or their partner get Child Benefit for), so their income is reduced by 11% before the rate is applied: £500 minus 11% (£55) = £445.
3. The Basic rate percentage for 2 children (16%) is then applied to the reduced figure: 16% of £445 = £71.20.
4. Weekly amount: £71.20.

Example 6: Flat rate A paying parent with gross weekly income of £75 falls in the Flat rate band (£7 to £100) and pays a flat £7 a week, regardless of exactly where their income sits within that band or how many qualifying children there are. The same £7 flat rate also applies where the paying parent is receiving certain benefits, whatever their reported income.

Example 7: Nil rate A paying parent with gross weekly income under £7 a week is assessed at the Nil rate and pays nothing. The Nil rate also applies in other circumstances set out in the regulations, such as where the paying parent is in prison or is themselves a child under 16. A full-time student with no income does not have to pay either, because student grants and loans do not count as income.

The table below summarises the worked examples above.

Estimate Only: Use the Calculator for Your Own Figures

Every figure in the worked examples above is an illustration of the statutory formula, using illustrative income and children figures to show the mechanics of the calculation. A real CMS assessment depends on verified HMRC income data, the specific number of qualifying and relevant other children, the actual shared-care pattern, and any variations the CMS applies for the paying parent's particular circumstances.

Only the Child Maintenance Service can produce a binding calculation for an individual case. For an estimate based on your own figures, use the child maintenance calculator, which applies this same formula and shows its full working; it is an estimate only, and the CMS's own assessment is what actually determines the amount due.

Direct Pay vs Collect and Pay

Once the CMS has calculated the maintenance, parents choose, or are moved onto, one of two payment routes. Direct Pay means the CMS tells both parents the calculated amount and the parents arrange the actual transfers between themselves, with no fee for either side. Collect and Pay means the CMS itself collects the money from the paying parent and passes it to the receiving parent, which carries a collection fee: 20% on top of the maintenance amount for the paying parent, and 4% deducted from what the receiving parent gets. Collect and Pay is typically used where there is a history of missed payments or where one parent does not want direct contact with the other.

Applying to the Child Maintenance Service

Applying to the CMS is free for everyone. The one-off £20 application fee that used to apply was abolished in Great Britain from 26 February 2024, under the Child Support (Management of Payments and Arrears and Fees) (Amendment) Regulations 2024 (SI 2024/87). Beyond the application itself, the Collect and Pay percentages set out above apply, and a paying parent who does not pay can also be charged enforcement fees (for example £300 when the CMS applies for a liability order); there is no separate charge simply for having a case calculated.

Northern Ireland: A Separate but Mirrored Scheme

Child maintenance in Northern Ireland is not handled by the same CMS as Great Britain. Northern Ireland has its own Child Maintenance Service, run by the Department for Communities, operating under its own legislation. In practice, the rates, bands, other-children reduction, shared-care bands, and Direct Pay and Collect and Pay fees all mirror the scheme used in England, Wales and Scotland. Applying to the Northern Ireland Child Maintenance Service is free too; Northern Ireland never introduced the £20 application fee that Great Britain charged until 2024. A parent in Northern Ireland applies through the Northern Ireland Child Maintenance Service rather than the GB service, but should expect the same calculation to apply to their case.

Use our child maintenance calculator to run the statutory formula against your own figures. If you were never married to the other parent, cohabiting couples' rights explains how that differs from child maintenance. Child maintenance also continues to apply during and after a divorce, separately from any financial settlement. For the full picture across nations, see our UK family law hub, part of our wider guide to United Kingdom law.

This article explains how the Child Maintenance Service formula works in general terms; it is not legal or financial advice, and it is not a substitute for a CMS calculation. Only the CMS can make a binding assessment for a particular family, and any figures here are estimates only. If you need to apply, or you disagree with an existing calculation, contact the Child Maintenance Service directly, or get free guidance from the government's Get Help Arranging Child Maintenance service, Gingerbread or Citizens Advice. Family separation is difficult for everyone involved, and support is available regardless of which parent you are.

Frequently Asked Questions

How is child maintenance calculated in the UK?

Where the Child Maintenance Service is used, it works out child maintenance using the paying parent's gross weekly income, taken from HMRC data, and applies one of five rates: Nil, Flat, Reduced, Basic or Basic Plus, depending on that income. Further reductions apply for other children in the paying parent's household and for shared overnight care.

What is the basic rate of child maintenance?

The Basic rate applies to gross weekly income between £200 and £800, and is charged as 12% of that income for one child, 16% for two children, or 19% for three or more children.

Is child maintenance based on gross or net income?

It is based on gross weekly income, meaning income before tax and National Insurance, but after deducting pension contributions (contributions an employer deducts from pay before tax are already reflected in the HMRC figure; other contributions, such as payments made directly to a private pension provider, are deducted if the paying parent asks the CMS and provides the details). The figure normally comes from HMRC records rather than payslips.

What happens if the paying parent earns over £3,000 a week?

Gross weekly income above £3,000 is ignored by the CMS formula. The receiving parent can apply to a court separately for a top-up order if they believe the paying parent's resources justify more.

What is the difference between Direct Pay and Collect and Pay?

With Direct Pay, the CMS calculates the amount but the parents arrange payment between themselves, with no fee. With Collect and Pay, the CMS collects and passes on the money, charging the paying parent 20% extra and deducting 4% from the receiving parent.

Does shared care reduce child maintenance?

Yes. Overnight stays with the paying parent reduce the weekly amount in bands, from a one-seventh reduction at 52 to 103 nights a year up to a one-half reduction plus a further £7 a week off at 175 nights or more.

How much does it cost to apply for child maintenance?

Applying to the Child Maintenance Service is free for everyone. The £20 application fee that applied in Great Britain was abolished from 26 February 2024; Northern Ireland never charged one. Collect and Pay carries its own ongoing percentage fees on top of the maintenance itself.

Does Northern Ireland use the same rules as the rest of the UK?

Northern Ireland has its own Child Maintenance Service under the Department for Communities, separate from the Great Britain scheme, but its rates and rules mirror the CMS formula used in England, Wales and Scotland.

Does having other children reduce how much I pay?

Yes, at the basic and basic-plus rates. If the paying parent, or their partner, gets Child Benefit for other children living with them, the paying parent's gross weekly income is reduced by 11% for one other child, 14% for two, or 16% for three or more, before the rate is applied.

What is the minimum amount of child maintenance?

The flat rate is £7 a week, which applies where gross weekly income is between £7 and £100, or where the paying parent gets certain benefits. Below £7 a week gross weekly income, the nil rate applies and no maintenance is due, subject to a few other circumstances such as being in prison; a full-time student with no income does not have to pay either.

Are the worked examples on this page exactly what I will pay or receive?

No. The worked examples show how the statutory formula works using illustrative figures. An actual assessment depends on the specific facts of a case, verified HMRC income data, and any variations the CMS applies. The Child Maintenance Service makes the binding calculation, not this page or the calculator.