Child Maintenance Calculator UK

Income Type

Paying Parent’s Gross Income

Number of Qualifying Children

Other Children Supported by Paying Parent

Does Paying Parent Receive Benefits?

Shared Care Nights per Year

How Child Maintenance Is Calculated

The Child Maintenance Service (CMS) uses a statutory formula to calculate child maintenance payments. The amount depends on the paying parent’s gross weekly income, the number of children involved, and whether there are any shared care arrangements.

Calculation Rates

The CMS applies different rates based on the paying parent’s gross weekly income:

Rate Type	Weekly Income Range	Payment Amount
Nil Rate	Below £7	£0
Flat Rate	£7 to £100 or on benefits	£7 per week
Reduced Rate	£100.01 to £199.99	£7 + percentage of income over £100
Basic Rate	£200 to £800	12% to 19% depending on children
Basic Plus Rate	£800.01 to £3,000	Basic rate + reduced percentage on excess
Default Rate	Income unknown	£38/£51/£64 for 1/2/3+ children

Basic Rate Percentages

For weekly income between £200 and £800:

1 child: 12% of gross weekly income
2 children: 16% of gross weekly income
3 or more children: 19% of gross weekly income

Basic Plus Rate Percentages

For weekly income over £800 (applied to income above £800 up to £3,000):

1 child: 9% of income over £800
2 children: 12% of income over £800
3 or more children: 15% of income over £800

Note: Income over £3,000 per week is not included in CMS calculations. Receiving parents can apply to courts for additional maintenance on income exceeding this threshold.

Reduced Rate Calculation

For weekly income between £100.01 and £199.99, the calculation is £7 plus a percentage of income over £100. The percentage varies depending on the number of qualifying children and other children supported:

Qualifying Children	Other Children	Percentage of Income Over £100
1	0	17%
1	1	14.1%
1	2	13.2%
1	3+	12.4%
2	0	25%
2	1	21.2%
2	2	19.9%
2	3+	18.9%
3+	0	31%
3+	1	26.4%
3+	2	24.9%
3+	3+	23.8%

Shared Care Reductions

Child maintenance is reduced when children stay overnight with the paying parent for at least 52 nights per year. The reduction applies to flat, reduced, and basic rates:

Nights per Year	Reduction Applied
0-51 nights	No reduction
52-103 nights	1/7 reduction
104-155 nights	2/7 reduction
156-174 nights	3/7 reduction
175+ nights	50% reduction plus £7 per child
182+ nights (equal care)	No payment required

Important: Child maintenance paid at basic, basic plus, or reduced rates cannot fall below £7 per week as a result of shared care adjustments.

When No Payment Is Required

The paying parent will not have to pay child maintenance if they are:

Sharing care equally with the other parent (182+ nights per year)
A full-time student with no income
In prison

Step-by-Step Calculation Guide

Step 1: Convert Income to Weekly Amount

All CMS calculations use gross weekly income. Convert annual or monthly income:

Annual income: Divide by 52
Monthly income: Multiply by 12, then divide by 52

Step 2: Determine the Applicable Rate

Based on the weekly income and circumstances, identify which rate applies (nil, flat, reduced, basic, or basic plus).

Step 3: Apply the Percentage

Calculate the maintenance amount using the appropriate percentage for the number of qualifying children.

Step 4: Account for Other Children

If the paying parent supports other children, this reduces the percentage applied (primarily affects reduced rate calculations and basic/basic plus rates through income adjustments).

Step 5: Apply Shared Care Reductions

If children spend 52 or more nights per year with the paying parent, reduce the calculated amount according to the shared care bands.

Step 6: Apply Minimum Threshold

Verify the final amount doesn’t fall below £7 per week (except for nil rate scenarios).

Example Calculation: A paying parent earns £30,000 annually (£576.92 weekly), has 1 qualifying child, and shared care of 60 nights per year. Weekly income of £576.92 falls into basic rate: £576.92 × 12% = £69.23. With 60 nights shared care (52-103 band), apply 1/7 reduction: £69.23 – (£69.23 ÷ 7) = £59.34 per week.

Frequently Asked Questions

What income is included in the calculation?

Gross income includes salary, wages, bonuses, pension income (including State Pension), and most other taxable income. It does not include benefits received for the qualifying children or certain disability benefits.

Can child maintenance be paid for children over 16?

Yes, child maintenance can be paid for children up to age 20 if they are in full-time non-advanced education (such as A-levels or equivalent), or if they are aged 16-17 and not in full-time education.

What if the paying parent is self-employed?

For self-employed parents, CMS uses income from the most recent tax year for which HMRC has information. This is typically based on the Self Assessment tax return. The calculation may be reviewed annually when new tax information becomes available.

How often are payments reviewed?

CMS reviews child maintenance calculations annually. Either parent can request a review if circumstances change significantly, such as a substantial change in income, changes to the number of children, or changes to shared care arrangements.

What if income changes during the year?

If the paying parent’s income changes by at least 25%, either parent can request a variation. CMS will reassess the calculation based on current income evidence. Changes must be reported within one month for CMS-arranged maintenance.

Does overnight contact need to be regular?

Shared care nights should follow a regular pattern, either agreed between parents or specified in a court order. One-off or irregular overnight stays may not count towards shared care reductions unless they form part of a consistent arrangement.

Can parents agree a different amount?

Yes, parents can make a family-based arrangement and agree any amount between themselves. The CMS calculation serves as a guide. However, if using the CMS service to arrange and collect payments, the statutory calculation will apply.

What happens if the paying parent refuses to pay?

CMS has enforcement powers including deduction from earnings orders, deduction from bank accounts, court action, removal of driving licence, and as a last resort, imprisonment. CMS can also charge collection fees to paying parents who miss payments.

Are there any additional costs or fees?

Using CMS to calculate maintenance is free. However, if CMS collects and transfers payments, they charge a 20% collection fee to the paying parent and a 4% receiving fee from the maintenance amount. Family-based arrangements avoid these fees.

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

CMS calculations cap at £3,000 gross weekly income (£156,000 annually). For income exceeding this, the receiving parent can apply to family courts for a ‘top-up’ order to cover the additional income not included in the CMS calculation.

Private Arrangements vs CMS Service

Family-Based Arrangements

Parents can agree child maintenance privately without involving CMS. Benefits include:

No application or collection fees
Flexibility to agree amounts and payment schedules
Faster to arrange than CMS applications
Can include non-financial support arrangements

Consideration: Private arrangements rely on trust and cooperation. There are no enforcement mechanisms if payments stop, though parents can apply to CMS later if needed.

CMS Service

Using the Child Maintenance Service provides:

Statutory calculation based on income evidence
Regular reviews and updates
Collection service (with fees) if parents cannot arrange directly
Enforcement powers if payments are missed
HMRC income verification for employed parents

Making the Choice

Consider a family-based arrangement if both parents communicate well and can agree terms. The CMS calculator can provide a starting point for discussions. Choose CMS service if there are concerns about payment reliability, income transparency, or if previous arrangements have failed.

Special Circumstances and Variations

Pension Contributions

Paying parents can apply for a variation if they make pension contributions exceeding certain thresholds. CMS may reduce the income used in calculations to account for legitimate pension payments.

Multiple Child Maintenance Cases

If the paying parent has child maintenance obligations for children in different households, each case is calculated separately. However, the presence of other qualifying children affects the percentage applied in each case.

Special Expenses

Variations can be requested for certain special expenses including:

Contact costs for seeing the qualifying children (travel, accommodation)
Costs relating to long-term illness or disability of a relevant child
Boarding school fees or essential school uniform costs
Mortgage or loan payments on the former family home if the receiving parent still lives there

Additional Income

Receiving parents can request a variation if the paying parent has additional income not captured in the standard calculation, such as:

Income from investments or property (exceeding £2,500 annually)
Assets diverted to reduce child maintenance liability
Lifestyle inconsistent with declared income

References

Department for Work and Pensions. Child Maintenance Service: How We Work Out Child Maintenance. GOV.UK. Available at: https://www.gov.uk/how-child-maintenance-is-worked-out
Department for Work and Pensions. Calculate Your Child Maintenance. GOV.UK. Available at: https://www.gov.uk/calculate-child-maintenance
Department for Communities Northern Ireland. Child Maintenance Rates Explained. NIDirect. Available at: https://www.nidirect.gov.uk/articles/child-maintenance-rates-explained
Department for Communities Northern Ireland. Shared Care in Child Maintenance Cases. NIDirect. Available at: https://www.nidirect.gov.uk/articles/shared-care-child-maintenance-cases
Gingerbread. Using the Child Maintenance Service (CMS). Available at: https://www.gingerbread.org.uk/find-information/money/child-maintenance/using-cms/
One Parent Families Scotland. How Much Child Maintenance Will I Get Paid? Available at: https://opfs.org.uk/support-and-advice/your-children/child-maintenance-arrangements/how-much-child-maintenance-will-i-get-paid/
Child Maintenance Options. Telephone: 0800 953 0191. Available Monday to Friday, 8am to 8pm.