Child Maintenance Service UK 2026: How Payments Are Calculated
The Child Maintenance Service (CMS) uses a gross income formula to set how much a non-resident parent must pay toward their child's upbringing. This guide explains every step of the 2026 calculation -- from how HMRC income data feeds the assessment, through flat, reduced and basic rates, to shared care reductions, variation requests and enforcement. Whether you are the paying parent trying to understand your liability or the receiving parent checking a calculation looks right, you will find a clear breakdown here.
What Is the Child Maintenance Service?
The Child Maintenance Service is the UK government body responsible for calculating and collecting financial support from a parent who does not live with their child. It replaced the Child Support Agency (CSA) for new applications from 2012 onwards and is run by the Department for Work and Pensions.
Before turning to the CMS, separating parents are encouraged to reach a family-based arrangement -- a private agreement without government involvement. These arrangements are free, flexible and often easier to adjust as circumstances change. If parents cannot agree, mediation is the next option. The CMS becomes relevant when no agreement can be reached or when a private arrangement breaks down and the receiving parent needs enforcement support.
Applying to the CMS costs GBP 20 (waived for victims of domestic abuse and for young people under 19 applying on their own behalf). Once an application is accepted, the CMS contacts the paying parent to gather information, then requests gross income data from HMRC. A calculation is issued to both parents, normally within six weeks of the application.
The CMS operates two payment methods. Under "Direct Pay," the paying parent transfers money directly to the receiving parent and the CMS monitors compliance without handling money itself -- there is no additional fee for this. Under "Collect and Pay," the CMS collects from the paying parent and passes it on, charging the paying parent an extra 20% fee and deducting 4% from each payment before it reaches the receiving parent. Most parents are encouraged to use Direct Pay where trust between them allows it.
How Gross Income Is Assessed
The CMS bases its calculation on the paying parent's gross annual income as reported to HMRC. Gross income means income before tax and National Insurance deductions but the CMS uses the figure supplied by HMRC rather than performing its own tax calculation. The most recent complete tax year for which HMRC has data is used as the starting point.
Employment income (including salary, wages, bonuses and commission) is included. Self-employment income is taken from the taxable profit figure on the Self Assessment return. Occupational and personal pension income counts. Certain state benefits also count -- including contributory Employment and Support Allowance and carer's allowance -- but Universal Credit, Housing Benefit, income-based Jobseeker's Allowance and similar means-tested benefits do not.
One important quirk: pension contributions do not reduce the gross income figure used by the CMS even though they reduce taxable income. If a paying parent contributes GBP 10,000 per year into a workplace pension, HMRC's assessment of their taxable income is already reduced by that amount, but the CMS adds those contributions back before applying the maintenance calculation. This prevents paying parents from sheltering income through pension contributions to reduce maintenance.
If the paying parent's income has gone up or down by 25% or more since the tax year being used, a "current income" change can be requested. The CMS will then use a projection of the current year's income instead. Evidence such as recent payslips or a business accountant's estimate will be required.
The Five CMS Calculation Rates Explained
The CMS applies one of five rates depending on the paying parent's gross weekly income. Converting annual gross income to a weekly figure is straightforward: divide the annual amount by 52.
Nil Rate
No maintenance is payable if the paying parent's gross weekly income is below GBP 7, or if they are a full-time student, aged 16 or 17 in full-time non-advanced education, a prisoner, or receiving certain income-related benefits such as income-based Jobseeker's Allowance or Income Support.
Flat Rate -- GBP 7 Per Week
A flat rate of GBP 7 per week applies when gross weekly income is between GBP 7 and GBP 100, or when the paying parent receives certain state benefits (including contribution-based ESA, carer's allowance or certain pensions). This flat GBP 7 is per case, not per child.
Reduced Rate -- GBP 100 to GBP 199.99 Per Week
Where gross weekly income falls between GBP 100 and GBP 199.99, a reduced rate formula applies. The calculation starts at GBP 7 and adds a percentage of the income above GBP 100. For one qualifying child, 17% of income above GBP 100 is added to GBP 7; for two children, 25% is added; for three or more, 31% is added. So a paying parent earning GBP 150 per week gross with one qualifying child would pay GBP 7 plus 17% of GBP 50, which equals GBP 7 plus GBP 8.50, giving GBP 15.50 per week.
Basic Rate -- GBP 200 to GBP 3,000 Per Week
Most CMS cases fall into the basic rate band. A percentage of gross weekly income is applied depending on the number of qualifying children:
One qualifying child: 12% of gross weekly income
Two qualifying children: 16% of gross weekly income
Three or more qualifying children: 19% of gross weekly income
For example, a paying parent earning GBP 600 per week gross with two qualifying children would owe 16% of GBP 600 = GBP 96 per week before any shared care or household child reductions.
Basic Plus Rate -- Above GBP 3,000 Per Week
For paying parents with gross weekly income above GBP 3,000, the basic rate percentages apply to the first GBP 3,000 and then additional percentages apply to income above that threshold. The additional percentages are 9% per child for one child, 12% for two, and 15% for three or more. Income above GBP 3,000 per week is capped at GBP 800 per week of additional maintenance liability. Very high earners who believe the formula underestimates the child's financial needs can apply to the courts for a "top-up" order under Schedule 1 of the Children Act 1989.
Reductions: Shared Care and Other Children
Shared Care Overnight Reductions
When the paying parent has a qualifying child staying overnight with them, the weekly maintenance figure is reduced to reflect that shared responsibility. The number of overnight stays per year determines the reduction band:
52 to 103 nights per year (one to two nights per week on average): reduce by one seventh
104 to 155 nights per year: reduce by two sevenths
156 to 174 nights per year: reduce by three sevenths
175 nights or more: reduce by one half, then subtract GBP 7 per week
The reductions are applied to the weekly maintenance figure that results from the rate calculation. Both parents must agree on the overnight figure, or evidence must be provided. Informal arrangements that are not consistently followed can be challenged by either parent at review.
Household Child Reduction
If the paying parent has other children (natural or adopted, not step-children) living with them full time, the gross income used in the calculation is reduced before the basic rate percentages are applied:
One other child in the household: gross income reduced by one fifteenth (approximately 6.67%)
Two other children: reduced by one tenth (10%)
Three or more other children: reduced by one seventh (approximately 14.3%)
This reduction recognises that the paying parent has an ongoing financial duty to children they live with. Evidence of the children's residence -- such as child benefit records or school registration -- may be requested by the CMS.
Variations: When Standard Income Is Not the Full Picture
Either parent can apply for a "variation" to change the income figure the CMS uses. Variations are particularly common where the paying parent is self-employed, runs a company, or holds significant assets.
Grounds for a Variation
The most frequently used variation grounds are:
Unearned income: Dividends, rental income, bank interest and other investment returns above GBP 2,500 per year that do not appear in the HMRC employment or self-employment figures can be added to the income used for calculation.
Income from assets: If the paying parent holds assets -- including property, shares or savings -- worth more than GBP 31,250 that produce little or no income, the CMS can deem a notional return of 8% per year on those assets and add it to the income figure.
Lifestyle inconsistency: If the paying parent's declared income appears inconsistent with their apparent standard of living (for example, owning an expensive home or car while declaring minimal income), the receiving parent can request a lifestyle variation. The CMS then investigates further.
Diversion of income: If the paying parent routes money through a company or to a third party specifically to reduce their maintenance liability, the CMS can look through the arrangement and include the diverted income.
The paying parent can also request a variation to reduce their income. Grounds include high travel costs to work (above GBP 10 per week and more than 150 miles per week), certain debts taken out before the relationship ended to benefit the family, and boarding school fees paid to benefit the qualifying child.
Director-Shareholders and the CMS
Owner-directors who pay themselves a low salary topped up with dividends are subject to close CMS scrutiny. The dividend income must be declared and the CMS can request company accounts. If the CMS believes salary has been artificially reduced to lower maintenance, it can apply a diversion of income variation. Retained profits sitting in a company do not automatically count, but if the paying parent has effective control over when dividends are paid, the CMS may argue the money is available to them.
Enforcement, Reviews and Appeals
Enforcement Options
When a paying parent misses payments under a Collect and Pay arrangement, the CMS has a wide range of enforcement tools. It can issue a Deduction from Earnings Order (DEO) instructing the employer to deduct maintenance directly from wages each pay period. For the self-employed, it can apply to the courts for a lump-sum Deduction Order against a bank or building society account.
If arrears accumulate and the paying parent continues to avoid payment, the CMS can apply to the Magistrates Court for a Liability Order. Once granted, this enables bailiff action, charging orders on property, and in persistent cases, removal of a driving licence for up to two years or commitment to prison for up to 42 days.
The CMS can also register a charge against a property under a Liability Order, meaning that if the property is sold the arrears are repaid from the proceeds before the paying parent receives any equity.
Annual Reviews
The CMS automatically reviews each case every year using updated HMRC income data. If the paying parent's income has changed, the maintenance amount is recalculated and both parents are notified. Either parent can also request an interim review at any point if income changes by 25% or more, if overnight stays change, or if a new child is born.
Mandatory Reconsideration and Appeals
If either parent believes the CMS has made a mistake, the first step is a Mandatory Reconsideration (MR). This must be requested within one month of the decision. The CMS reviews the case internally and issues a fresh decision. If the MR result is still unsatisfactory, an appeal to the First-tier Tribunal (Social Entitlement Chamber) can be lodged within one month of the MR decision. The tribunal is entirely independent of the CMS and can confirm, vary or set aside the CMS decision. Common appeal grounds include using incorrect income data, failing to apply a variation correctly, or errors in the overnight stays calculation.
Child Maintenance and Income Tax: What You Need to Know
Child maintenance payments are not tax deductible for the paying parent, nor are they taxable income for the receiving parent. This contrasts with spousal maintenance (also called periodical payments), which can in some circumstances have tax implications. Child maintenance sits outside the income tax system entirely.
Because child maintenance has no income tax effect, it also does not interact with the personal allowance (GBP 12,570 for 2026/27) or the higher and additional rate tax bands. However, the CMS calculation is based on gross income -- the income before tax is taken -- so a paying parent whose gross income is GBP 50,000 and who pays 40% income tax and 2% employee National Insurance on the income above GBP 50,270 will still have their maintenance calculated on the full GBP 50,000 gross figure.
Child Benefit interacts with child maintenance indirectly. Child Benefit is paid at GBP 26.05 per week for the first child and GBP 17.25 per week for each subsequent child in 2026/27. It is clawed back via the High Income Child Benefit Charge (HICBC) when either parent earns above GBP 60,000, with full clawback at GBP 80,000. Child Benefit payments are not counted as income by the CMS and do not reduce maintenance, but they represent a separate stream of financial support for the child that may influence how parents negotiate private arrangements.
Child maintenance payments are also fully disregarded in Universal Credit assessments. Whether the receiving parent gets GBP 50 per week or GBP 500 per week in maintenance, their UC award remains unchanged. This is a significant improvement over the old tax credits system, where maintenance could reduce entitlements.
Frequently Asked Questions
What is the Child Maintenance Service and who uses it?
The Child Maintenance Service (CMS) is a government body that calculates, collects and enforces child maintenance payments when parents cannot agree privately. It replaced the Child Support Agency in 2012. Either parent can apply to the CMS if a private agreement breaks down or cannot be reached. The paying parent -- typically the one with whom the child spends less time -- pays maintenance to the receiving parent. The CMS charges a GBP 20 application fee (waived for victims of domestic abuse and under-19s applying for themselves) and takes a 20% collection fee from the paying parent plus a 4% deduction from money passed to the receiving parent if it manages the collection.
How does the CMS calculate the gross income used for child maintenance?
The CMS uses gross annual income from HMRC records as its starting point. This includes employment income, self-employment profits, pension income and certain benefits. For the most recent tax year available, HMRC provides the figure directly to the CMS. If income has changed by 25% or more since the tax year used, either parent can request a variation. The CMS also adds back pension contributions into the gross figure for assessment purposes, which often surprises people who expected those contributions to reduce the maintenance amount. Investment income above GBP 2,500 per year may also be included following a variation request.
What are the main CMS calculation rates for 2026?
The CMS uses five rates based on the paying parent's gross weekly income. The nil rate applies when income is below GBP 7 per week or the paying parent is a student, prisoner, 16-17 year old in education or receiving certain benefits. The flat rate of GBP 7 per week applies when gross income is below GBP 100 per week or the paying parent receives certain state benefits. The reduced rate applies between GBP 100 and GBP 199.99 per week, calculated using a sliding formula. The basic rate applies from GBP 200 to GBP 3,000 per week: 12% for one child, 16% for two children, 19% for three or more. The basic plus rate applies above GBP 3,000 per week with additional percentages on the excess.
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How does shared care reduce child maintenance payments?
If the paying parent has the child staying overnight for 52 or more nights per year (on average one night per week), a shared care reduction applies. The reduction is one seventh (roughly 14.3%) per band of overnight stays. For 52 to 103 nights per year the reduction is one seventh; for 104 to 155 nights it is two sevenths; for 156 to 174 nights it is three sevenths; for 175 nights or more it is one half minus GBP 7. The number of nights is agreed or disputed between the parents, and if disputed the CMS may require evidence. Shared care reductions are applied to the calculated weekly maintenance figure before any collection service fees are added.
What happens when the paying parent has children in their household?
The CMS makes a reduction to gross income before applying the basic rate percentages if the paying parent has other children living with them who they are responsible for. For one other child in the household, gross income is reduced by one fifteenth before calculation. For two other children the reduction is one tenth, and for three or more other children the reduction is one seventh. This recognises that the paying parent has ongoing financial obligations to children at home. Step-children do not qualify for this reduction -- only natural or adopted children for whom the paying parent is financially responsible count toward the household child reduction.
Can the CMS consider assets and lifestyle if income looks artificially low?
Yes. A "variation" application allows either parent to ask the CMS to look beyond the gross income figure from HMRC. Grounds for variation include unearned income (dividends, rental income, interest above GBP 2,500), assets worth over GBP 31,250 that are not producing income, lifestyle inconsistent with declared income, and income diverted through a business or to a third party. If the CMS agrees the variation is justified, it recalculates maintenance on an adjusted income figure. Variations can significantly increase the maintenance amount for paying parents who own property, hold investments or run their own company where salary can be kept artificially low.
What enforcement powers does the CMS have if a paying parent refuses to pay?
The CMS has extensive enforcement powers. It can make a Deduction from Earnings Order (DEO), instructing an employer to deduct maintenance directly from wages before they are paid. For the self-employed or those with irregular income it can apply to court for a lump sum Deduction Order against a bank account. If arrears build up, the CMS can apply for a Liability Order from the Magistrates Court, then use bailiffs, place a charging order on property, disqualify the paying parent from driving for up to two years, or apply for a curfew order. In serious cases of persistent non-payment the CMS can apply for committal to prison for up to 42 days.
How do I challenge a CMS decision I think is wrong?
If you disagree with a CMS calculation or decision, the first step is a Mandatory Reconsideration (MR). You must request this within one month of the decision letter. The CMS reviews the case internally and issues a new decision. If you still disagree after the MR, you can appeal to the Social Entitlement Chamber of the First-tier Tribunal within one month of the MR decision. Tribunals are independent of the CMS and can overturn or vary decisions. Common grounds for challenge include using the wrong income year, failing to apply a variation correctly, or arithmetic errors. Getting specialist advice from a family law solicitor or Citizens Advice before an appeal is strongly recommended.
Does child maintenance affect Universal Credit or other benefits?
Child maintenance payments are completely disregarded when calculating Universal Credit. Whether you pay or receive maintenance, the amount does not reduce UC entitlement or count as income for UC purposes. This policy has been in place since UC replaced legacy benefits. However, if you are the receiving parent and have a large amount of savings built up from maintenance payments, those savings could affect means-tested benefit entitlement once they exceed the relevant capital thresholds. Maintenance also does not count as income for Council Tax Reduction purposes in most local authority schemes, though rules vary slightly by council.
When does child maintenance stop and can it continue beyond 18?
Child maintenance calculated by the CMS automatically stops when the child turns 16. If the child is in full-time non-advanced education -- such as A-levels or a BTEC at school or college -- maintenance continues until the child turns 20 or leaves education, whichever is earlier. University or higher education does not count for CMS purposes, so maintenance stops at 20 regardless of whether the child is at university. However, parents can make a voluntary private agreement to continue supporting a child through university, and some court orders made before 2003 under the old system may continue past 18. Parents should review the case closing date and agree any voluntary arrangements in writing.
