Variation Grounds Checker

What a variation actually is

The standard calculation is deliberately crude. It takes one number, gross taxable income from HMRC for the latest available tax year, and applies fixed percentages to it. That works for a salaried employee. It works badly for a company director, a landlord, or a parent paying hundreds of pounds a month just to see their child.

A variation is the formal route to adjust for that. Regulations 63 to 71 of the Child Support Maintenance Calculation Regulations 2012 set out the grounds. Nothing happens automatically. One parent has to apply, name the ground, and produce evidence. Left alone, the formula result stands.

Grounds that reduce the assessment: special expenses

These are for the paying parent. Each category has to clear £10 a week before it counts, and each has to be evidenced.

Two things trip applicants up. The £10 threshold is per category, not across the total, so three small costs of £8 each add up to nothing. And these expenses come off income before the percentages are applied, so the effect on the weekly payment is smaller than the raw expense figure suggests. Run the numbers through the main CMS calculator before deciding whether an application is worth the effort.

Grounds that increase the assessment

Unearned income, regulation 69

Taxable income from property, savings, investments or dividends, with an annual threshold of £2,500. The employment figures the CMS pulls from HMRC do not include any of it. A director drawing £12,000 in salary and £70,000 in dividends looks, to the standard calculation, like a low earner. Regulation 69 exists precisely for that gap.

Notional income

Assets that could reasonably produce income but are not producing any. It is a narrower ground than most people expect and it is not a general wealth tax. Owning a valuable house you live in is not notional income. Holding capital that is deliberately parked so it generates nothing is closer to the mark.

Diversion of income, regulation 71

This applies where a parent has the ability to control the amount of income they receive and arranges matters so their liability falls. The classic patterns are a new partner on an inflated salary from the family company, profits retained in the business rather than drawn, and a director salary cut to the minimum in the same month a maintenance case opens.

Two conditions have to be met: control and diversion. Someone who genuinely earns less than they used to has not diverted anything. Someone who signs their own payroll has a case to answer. That distinction decides most of these applications.

A worked example: the director on a small salary

A paying parent owns their own limited company. They take a salary of £12,000 a year and £48,000 in dividends. One qualifying child, no shared care, no other children in the household. Here is what the two routes produce.

The dividends clear the £2,500 annual threshold many times over, so they can be brought into the calculation. The gap between the two columns is £100.16 a week, which is over £5,200 a year. Nothing about the standard calculation is wrong in a technical sense. It simply looked at the only number it was given.

This is why the receiving parent's side of the variation rules matters so much in practice. The salary is real, HMRC has it, and the CMS will use it without hesitation. The dividends sit in a self assessment return and in company accounts that nobody at the CMS is going to open unless somebody asks them to.

Where the official position is contested

The mirror image applies to paying parents. Special expenses that are real and evidenced are still ignored unless someone applies for them. The formula does not look for reasons to reduce a liability any more than it looks for hidden income. It applies percentages to one number and stops.

Building an application that survives scrutiny

1. Name the regulation. Write down which ground you are relying on rather than describing a general sense of unfairness.
2. Quantify it. State the annual figure and how you arrived at it, whether that is dividend vouchers or a mileage total.
3. Attach documents. Companies House filings, dividend vouchers, Land Registry entries, accounts, invoices and receipts all carry weight.
4. Keep lifestyle evidence in its place. Photographs of a new car support a story but do not prove income on their own.
5. Record every date. When you applied, when you sent evidence, who you spoke to and what they said.

The last point matters more than it looks. If a variation is granted, the effective date decides how much money actually changes hands, and that date is usually tied to when you applied rather than when the circumstances began. A well documented application date is worth real money.

What the standard formula does with the result

A granted variation feeds back into the same bands. Basic rate is 12% of gross weekly income for one child, 16% for two, and 19% for three or more, on income between £200 and £800 a week. Above £800 the excess up to £3,000 is charged at 9%, 12% or 15%. Anything above £3,000 a week is ignored, and section 8 of the Child Support Act 1991 keeps the courts out of most cases, so there is no easy alternative route once you hit that ceiling.

Other children living with the paying parent still come off first, reducing gross income by 11%, 14% or 16% depending on how many. Shared care still reduces the total afterwards, by a seventh at 52 to 103 nights, two sevenths at 104 to 155, three sevenths at 156 to 174, and a half plus £7 per child per week at 175 nights or more. A variation changes the input, not the machinery.

Which is worth remembering before you apply. A variation that adds £5,000 of unearned income to a case already sitting in the basic plus band adds far less to the weekly payment than the same £5,000 added to a case in the basic rate band, because the excess above £800 a week is charged at the lower percentages. Work out the likely gain first, then decide whether the evidence gathering is worth it.

If the variation is refused

Refusals are common, and a refusal is not the end. Request a mandatory reconsideration within one calendar month of the decision. That step is compulsory before any appeal. Our mandatory reconsideration tool walks through what to include. If the reconsideration fails, the decision can be appealed to the First-tier Tribunal, which is independent of the CMS.

Where the problem is delay or poor handling rather than the decision itself, the complaints route is separate and runs in parallel. The complaint letter generator covers that. If a variation is granted and money is owed, the arrears calculator will show the balance, and the income change checker is the tool to use if the underlying earnings have moved rather than the grounds. Our article library goes into each ground in more detail.

Common questions