Child Maintenance Calculator UK
Estimate weekly and annual Child Maintenance Service (CMS) payments under the 2012 scheme — nil, flat, reduced, basic and basic plus rates, with other-children and shared-care adjustments.
CMS 2012 scheme rates — estimate weekly and annual child maintenance
Gross income, after pension contributions are deducted.
Simplified: one shared-care band is applied to every qualifying child.
How CMS calculates child maintenance
The Child Maintenance Service (CMS) 2012 scheme applies one of five rates to the paying parent's gross weekly income (after pension contributions are deducted).
| Rate | Gross weekly income | How it's calculated |
|---|---|---|
| Nil | Under £7.00 | £0 (also applies to students, prisoners, under-16s and some 16-19 year olds) |
| Flat | £7.00-£100.00 | £7.00/week flat — also applies if the paying parent is on qualifying benefits |
| Reduced | £100.00-£200.00 | £7.00 plus a percentage of income over £100.00 (see matrix below) |
| Basic | £200.00-£800.00 | 12% / 16% / 19% of gross weekly income for 1 / 2 / 3+ children |
| Basic plus | £800.00-£3,000.00 | Basic rate on the first £800.00, plus 9% / 12% / 15% on the portion above it |
Income above £3,000.00/week is capped for the CMS formula — the receiving parent can apply to the courts for extra maintenance above this level. If CMS cannot establish the paying parent's income, it can apply a default rate of £38.00 / £51.00 / £64.00 per week for 1 / 2 / 3+ children.
Other-children reduction
Before the rate above is applied, the paying parent's gross weekly income is reduced if they (or their partner) receive Child Benefit for other children.
| Other children supported | Income reduction |
|---|---|
| None | No reduction |
| 1 | 11% |
| 2 | 14% |
| 3 or more | 16% |
At the reduced rate, the percentage applied to income between £100.00 and £200.00 also depends on how many other children are supported:
| Qualifying children | No other children | 1 other child | 2 other children | 3+ other children |
|---|---|---|---|---|
| 1 | 17% | 14.1% | 13.2% | 12.4% |
| 2 | 25% | 21.2% | 19.9% | 18.9% |
| 3 or more | 31% | 26.4% | 24.9% | 23.8% |
Shared care reduction
If the qualifying child stays overnight with the paying parent for 52 or more nights a year, the maintenance amount is reduced. This calculator applies one shared-care band to all qualifying children as a simplification — CMS actually assesses shared care per child.
| Nights per year | Cut to maintenance |
|---|---|
| 52 to 103 nights a year (1 night a week or more) | 1/7th |
| 104 to 155 nights a year (2 nights a week or more) | 2/7ths |
| 156 to 174 nights a year (3 nights a week or more) | 3/7ths |
| 175 nights or more a year (roughly equal shared care) | 50% plus an extra £7.00/week per child |
Maintenance at the basic, basic plus or reduced rate cannot fall below £7.00/week as a result of the shared-care adjustment. At the flat rate, 52+ nights of shared care reduces the liability to nil.
Worked examples
£150/week, 1 child, no other children
£15.50/wk
Reduced rate: £7.00 + 17% of the £50 over £100.00
£500/week, 2 children, 1 other child
£71.20/wk
Income reduced to £445.00, then basic rate applied
£1,000/week, 2 children, 104-155 nights shared care
£108.57/wk
Basic plus rate £152.00, cut by 2/7ths for shared care
Frequently asked questions
How is child maintenance calculated in the UK?
The Child Maintenance Service (CMS) 2012 scheme uses the paying parent's gross weekly income (after pension contributions) to apply one of five rates: nil (income under £7.00), flat (£7.00/week for income £7.00-£100.00, or if on qualifying benefits), reduced (£100.00-£200.00 income), basic (£200.00-£800.00), and basic plus (up to the £3,000.00/week cap). Income is first reduced if the paying parent supports other children, then the rate and percentage are applied.
What if the paying parent supports other children?
Before the rate is worked out, CMS reduces the paying parent's gross weekly income by 11% for 1 other child, 14% for 2, or 16% for 3 or more — "other children" meaning children the paying parent or their partner receives Child Benefit for. This can move income into a lower rate band before the reduced-rate percentage is applied.
How does shared care reduce child maintenance?
If the paying parent has the child overnight for 52 or more nights a year, the maintenance amount is cut: 1/7th for 52-103 nights, 2/7ths for 104-155 nights, 3/7ths for 156-174 nights, and 50% plus an extra £7.00/week per child for 175+ nights. Maintenance at the basic, basic plus or reduced rate cannot fall below £7.00/week as a result of this adjustment. At the flat rate, 52+ nights of shared care reduces the liability to nil.
Is there a maximum income for child maintenance?
Yes. Gross weekly income above £3,000.00 is capped for the CMS formula — the calculation stops at £3,000.00/week. If the paying parent earns more than this, the receiving parent can apply to the courts for a "top-up" order for additional maintenance.
Is child maintenance taxable?
No. Child maintenance is not taxable income for the parent receiving it, and it is not tax-deductible for the parent paying it. It has no impact on either parent's Income Tax or Self Assessment.
Does child maintenance affect Universal Credit?
Child maintenance payments received are fully disregarded as income for Universal Credit purposes — receiving maintenance does not reduce your UC award. Use our Universal Credit Calculator to check your award alongside any maintenance you receive.
What is the default rate if income is not known?
If CMS cannot establish the paying parent's income, it can apply a default rate of £38.00/week for 1 child, £51.00/week for 2 children, or £64.00/week for 3 or more children. This is a fallback used by CMS directly and is not one of the paths in this calculator.
Sources
Last updated July 2026. CMS 2012 scheme rates are not annually uprated — figures verified against gov.uk and nidirect.gov.uk July 2026.