Key facts
- Basic rate maintenance is 12% of gross weekly income for one child, 16% for two and 19% for three or more
- On £500 gross a week that is £60, £80 or £95 before any shared-care reduction
- Five CMS rates apply from nil below £7 a week to basic plus above £800 up to the £3,000 cap
- Shared care from 52 nights a year reduces the payment; the minimum is £7 a week
Child maintenance uses gross income, the same starting point as the tax explained in income tax bands guide and shown on your how to read your payslip guide.
| Gross weekly income | 1 child (12%) | 2 children (16%) | 3 or more (19%) |
|---|---|---|---|
| £300 | £36 | £48 | £57 |
| £500 | £60 | £80 | £95 |
| £700 | £84 | £112 | £133 |
| £800 | £96 | £128 | £152 |
Basic rate applies to gross weekly income of £200 to £800, before any shared-care reduction. Source: GOV.UK, WhatsUK calculation, June 2026.
The Child Maintenance Service uses five rates based on the paying parent's gross weekly income. The nil rate applies below £7 a week, the flat rate of £7 covers £7 to £100 a week or certain benefits, and the reduced rate applies from £100.01 to £199.99. The basic rate covers £200 to £800, and the basic plus rate adds a lower percentage on income between £800.01 and the £3,000 weekly cap.
Shared care reduces the payment based on the nights the child stays with the paying parent. From 52 to 103 nights a year cuts the amount by one seventh, 104 to 155 nights by two sevenths, and 156 to 174 nights by three sevenths. At 175 nights or more it is halved, with a further £7 a week reduction per child, though the payment never falls below £7 a week.
Budgeting around a regular payment is easier with a buffer, see emergency fund guide.
CMS vs Family-Based Arrangements
You do not have to use the CMS to arrange child maintenance. Many parents agree an amount directly between themselves, a family-based arrangement, which is often more flexible and avoids CMS fees. However, if you cannot reach agreement, one parent can apply to the CMS, which will calculate and, if necessary, collect and enforce payments.
How the CMS Calculates Child Maintenance
The CMS uses the paying parent's gross weekly income as the starting point. Gross income includes employment income, self-employed profits, rental income, and pension income. It is taken from HMRC tax records, usually the most recent tax year, then converted to a weekly figure.
The calculation then applies a percentage of gross income based on the number of children under the basic rate:
| Number of Children | % of Gross Weekly Income |
|---|---|
| 1 child | 12% |
| 2 children | 16% |
| 3 or more children | 19% |
These percentages apply to gross weekly income between £200 and £800 under the basic rate. Above £800.01, the basic plus rate uses 9%, 12% or 15% on the excess up to the £3,000 weekly cap.
The Five CMS Income Rates
| Gross Weekly Income | Rate | Notes |
|---|---|---|
| Below £7 | Nil rate | No maintenance through CMS |
| £7 to £100 | Flat rate | £7 a week, or certain benefits |
| £100.01 to £199.99 | Reduced rate | Fixed formula on income in this band |
| £200 to £800 | Basic rate | 12%, 16% or 19% by number of children |
| £800.01 to £3,000 | Basic plus rate | Basic rate on first £800, then 9%, 12% or 15% on excess |
Shared Care Reductions
If the paying parent has overnight stays with the child, the maintenance calculation is reduced. The more nights the paying parent has, the larger the reduction:
| Nights Per Week (Average) | Annual Nights | Reduction to Payment |
|---|---|---|
| Less than 1 night | Under 52 | No reduction |
| 1 night/week | 52 to 103 | 1/7 reduction |
| 2 nights/week | 104 to 155 | 2/7 reduction |
| 3 nights/week | 156 to 174 | 3/7 reduction |
| 3+ nights/week | 175 or more | Halved, plus £7/week reduction per child |
Shared Care Example
Paying parent earns £36,000 gross (£692/week). One child. Base maintenance: 12% x £692 = £83.04/week. Paying parent has the child 2 nights per week: reduction of 2/7 x £83.04 = £23.73. Final weekly maintenance: £83.04 minus £23.73 = £59.31/week.Child Benefit is a separate HMRC payment to parents and carers. See our Child Benefit UK guide for weekly rates, eligibility, and the high earner charge. Use the calculator below for CMS maintenance amounts.
Child Maintenance Calculator
Enter the paying parent's gross income, number of children, and overnight nights to get the CMS calculation.
Other Income the CMS Considers
The CMS may consider income beyond employment salary in some cases:
- Unearned income: If investment, rental, or other income exceeds £2,500/year, the CMS may add it to the gross income figure
- Lifestyle inconsistency: If the paying parent's lifestyle appears inconsistent with their declared income, the CMS can investigate and impute income
- Pension contributions: Employer pension contributions are excluded; personal contributions are generally excluded too
- Children in other relationships: If the paying parent supports other children (not stepchildren), the income percentage is reduced
Grounds to Vary the Standard Calculation
Either parent can apply for a variation to the standard CMS calculation in specific circumstances:
- Special expenses (paying parent): High travel costs to see the child, boarding school fees, or costs of maintaining contact with a disabled child
- Additional income (receiving parent): Can request variation if the paying parent has significant assets, diversion of income through a business, or lifestyle inconsistent with declared income
- Property or assets: If the paying parent has significant capital assets not generating declared income, this may be considered
What Happens If Payments Aren't Made?
The CMS has significant enforcement powers when paying parents default. These include:
- Deduction from earnings: Direct deduction from wages, an employer is legally required to comply
- Deduction from bank account: Lump-sum or regular deduction orders from the paying parent's bank
- Bailiffs and enforcement: Sending bailiffs to seize and sell assets
- Driving licence removal: The CMS can apply to a court to disqualify the paying parent from driving
- Passport removal: Court can order confiscation of passport for persistent non-payment
- Imprisonment: Up to 2 years for wilful refusal to pay in contempt of court
Related Calculators
Frequently Asked Questions
The Child Maintenance Service uses the paying parent's gross weekly income and the number of children. Under the basic rate it is 12% of gross weekly income for one child, 16% for two, and 19% for three or more, then reduced for shared care. Different rates apply at very low and very high incomes.
Under the basic rate it is 12% of the paying parent's gross weekly income. On £500 a week that is £60, and on £700 a week it is £84. The figure is then reduced if the child stays overnight with the paying parent, and a higher cap applies once income passes £800 a week.
They depend on gross weekly income. The nil rate is below £7, the flat rate of £7 covers £7 to £100 or certain benefits, the reduced rate runs from £100.01 to £199.99, the basic rate covers £200 to £800, and the basic plus rate applies from £800.01 up to the £3,000 weekly cap.
The more nights the child spends with the paying parent, the lower the payment. From 52 nights a year it falls by one seventh, rising to a half once care reaches 175 nights, plus a further £7 a week per child. Even with substantial shared care, the payment does not drop below £7 a week.
The calculation uses the paying parent's gross weekly income, usually taken from HMRC records, before tax and National Insurance but after pension contributions. Annual figures are converted to weekly by dividing by 365 and multiplying by 7. Income above £3,000 a week is ignored for the calculation.
It applies to gross weekly income between £800.01 and £3,000. The first £800 is calculated at the basic rate, and the part above £800 uses lower percentages: 9% for one child, 12% for two and 15% for three or more. So a parent of two on £1,000 a week pays £128 plus £24, which is £152.
Usually yes, at the flat rate of £7 a week. The flat rate applies where gross weekly income is £100 or less, or where the paying parent receives certain benefits. It ensures a contribution continues even on a low income, unless a nil-rate situation such as being a full-time student applies.
No. Child maintenance is paid from income that has already been taxed, so the receiving parent does not pay tax on it and the paying parent gets no tax relief for it. It does not count as income for the receiving parent and does not affect their tax or most means-tested benefits.
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James Hartley is a Chartered Management Accountant (CIMA) with more than eight years of experience in UK tax, payroll and compliance. He holds a BSc in Finance and Economics from the University of Manchester and spent his early career at a Big 4 accounting firm. He founded WhatsUK to build free UK financial calculators and guides verified against official HMRC sources. He authors every calculator and article on WhatsUK.
Sources & Official References
- GOV.UK - Child Maintenance: How Much to Pay- Official CMS calculation methodology and rates
- GOV.UK - CMS Fees- 20% surcharge for paying parent, 4% deduction for receiving parent on Collect & Pay
- GOV.UK - Shared Care and Child Maintenance- Overnight stay reduction rates
- Child Maintenance Options Service- Free impartial guidance on all child maintenance arrangements
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Disclaimer: This calculator provides estimates based on standard HMRC rates for 2026/27. Results may vary based on individual circumstances. This is not financial advice. Always consult a qualified accountant or CIMA-qualified financial adviser for personal tax matters.