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.
Official next steps
Take the estimate into the CMS process
The calculation is only the starting point. Choose how to arrange payments, account for collection fees and report changes through the official service.
Apply to CMS
Compare a private arrangement with an official CMS case and prepare the required details.
Open guide →
Compare payment fees
See the current cash-flow difference between Direct Pay and Collect and Pay.
Open guide →
Report a change or missed payment
Use the CMS account for income, care, contact or payment changes.
Open guide →
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 prisoners, under-16s and some 16-19 year olds in full-time non-advanced education or approved training) |
| 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 £39.00 / £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. In this band the other children are accounted for by the percentage alone — the income reduction above applies only from £200.00/week upward:
| 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. Where the flat rate applies because the paying parent (or their partner) gets a qualifying benefit, 52+ nights of shared care reduces the liability to nil; where it applies because income is £100.00/week or less, shared care does not change the amount.
Counting overnight stays over a year
The Child Maintenance Service adds up the nights a child stays with the paying parent in a year and divides by 52. Two examples from GOV.UK’s guidance on living arrangements, counted night by night:
- Friday and Saturday every other week: 52 nights, an average of 1 a week.
- Two weeks at Christmas and six in the summer, nothing else: 56 nights, still about 1 a week.
A fixed weekly pattern can land on 52 or 53 nights depending on where the year starts, which is why the calculator’s Count overnight stays from a calendar option lists every night rather than multiplying by 52. It gives an estimate of the arrangement you enter; the Child Maintenance Service works from the usual arrangement and decides the band.
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). From £200.00/week income upward, 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?
Where gross weekly income is £200.00 or more, CMS reduces it by 11% for 1 other child, 14% for 2, or 16% for 3 or more before the rate percentage is applied — "other children" meaning children the paying parent or their partner receives Child Benefit for. Below £200.00/week there is no income reduction: at the reduced rate the other children are already built into the percentage table, so reducing income as well would count them twice.
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. Where the flat rate applies because the paying parent (or their partner) gets a qualifying benefit, 52+ nights of shared care reduces the liability to nil; where it applies because income is £100.00/week or less, shared care does not change the amount.
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. GOV.UK says child maintenance payments will not affect any benefits you and your children get, and the parent receiving them does not have to pay tax on them.
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 £39.00/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 August 2026. CMS 2012 scheme rates are not annually uprated — figures verified against legislation.gov.uk, gov.uk and nidirect.gov.uk August 2026.