"My ex is asking me to pay half of diapers, clothing, and groceries on top of child support. Is that right?" This is one of the most common questions in Canadian family law forums, and the answer is almost always no. The monthly child support table amount already covers ordinary, recurring costs of raising children. Section 7 of the Federal Child Support Guidelines (SOR/97-175) is a separate mechanism for sharing specific categories of large expenses that fall outside what the table amount is designed to cover.

This article explains which expenses qualify as Section 7 special or extraordinary expenses, how the net cost is calculated after tax benefits, and how each parent's proportional share is determined. We work through a concrete numerical example using the childcare deduction rules under the Income Tax Act.

What Base Child Support Covers — And What It Doesn't

The child support table amount is calculated based on the payor's income and the number of children. It is designed to cover the ordinary, recurring costs of raising children in a household: food, clothing, shelter, basic school supplies, routine transportation, and everyday activities. These are not itemized or tracked — the table amount is a lump sum intended to cover all of them.

Section 7 expenses are separate. They cover specific categories of large or extraordinary costs that arise on top of the daily basics — things like childcare needed so a parent can work, uninsured dental or medical treatments, and competitive sports programs. The two pools do not overlap: a parent cannot claim food, clothing, or basic school supplies as Section 7 expenses on top of the table amount they are already receiving.

The Two-Part Test — What Qualifies as a Section 7 Expense

Not every large expense qualifies. Section 7(1) of the Guidelines sets out a two-part test that every claimed expense must meet:

Within this framework, the Guidelines create two tiers of eligibility. Some categories are always shareable if they pass the two-part test:

The Childcare Eligibility Nuance

Childcare is one of the most commonly claimed Section 7 expenses, but it comes with an important condition: it must be required because the custodial parent is working, attending school, or has a health condition that prevents them from providing care. Childcare incurred during a parent's parenting time when that parent is available to care for the child may not qualify. Courts have scrutinized claims where one parent chose to use daycare during their custodial time despite being able to provide care themselves.

After separation (90 or more days apart), each parent claims their own childcare expenses independently for tax purposes. The lower-income attribution rule under ITA s.63(2) — which normally requires the lower-income spouse to claim the deduction — does not apply between separated parents. Each parent deducts the childcare they actually paid.

How the Net Cost Is Calculated

Parents do not split the gross cost of a Section 7 expense. The Guidelines require that the expense first be reduced to its net cost — the amount remaining after the child's own contributions, subsidies, and tax benefits are subtracted. Only the net cost is then divided between the parents.

For childcare specifically, the tax benefit comes from the childcare expense deduction under ITA s.63. The deductible amount is the lesser of: (a) per-child annual limits — $8,000 for each child under 7 at December 31, $5,000 for each child aged 7 to 16, and $11,000 for a child eligible for the disability tax credit; (b) two-thirds of the claiming parent's earned income; or (c) the total childcare expenses actually paid. The tax savings from this deduction depend on the claiming parent's marginal tax rate.

Dvorce.ca computes the tax benefit as the exact difference between running a full tax calculation with and without the childcare deduction — rather than applying an estimated marginal rate. This captures bracket crossovers, surtax interactions, and benefit clawbacks that a flat-rate estimate would miss.

How Each Parent's Share Is Determined

Once the net cost is calculated, it is divided between the parents in proportion to their respective guideline incomes. Each parent's share equals their guideline income divided by the combined guideline income of both parents. If spousal support is being paid, the payor's income is reduced by the spousal support amount and the recipient's income is increased by the same amount before the ratio is computed.

This means the Section 7 percentages change depending on the spousal support scenario. At higher spousal support amounts, the payor's adjusted income drops and their share of Section 7 expenses decreases. The calculator produces different S.7 percentages for each SSAG scenario (low, mid, high) for this reason.

An important technical point: the income base for Section 7 apportionment is pre-tax guideline income, not after-tax net disposable income (NDI). This is why the S.7 split and the NDI split never align — they use fundamentally different income definitions. For a deeper exploration of this structural disconnect, see our article on why your S.7 apportionment never matches your NDI split.

Worked Example — Childcare Expense

Consider two parents in Ontario with one child, age 4. Parent A earns $90,000 and Parent B earns $40,000. Parent A pays $6,000 per year in childcare so they can work. No spousal support is paid.

Parent A advances the full $6,000 in childcare costs, then claims the $2,600 tax benefit on their tax return. The net cost of $3,400 is split proportionally: Parent A bears $2,353 (69.2%) and Parent B owes $1,047 (30.8%), which works out to approximately $87 per month. In practice, Parent A bills Parent B for their share — typically monthly or quarterly, supported by receipts.

The tax benefit figure above is approximate — the actual amount depends on the claiming parent's full tax profile, including bracket crossovers and provincial surtaxes. The calculator runs the complete tax computation to produce the exact figure rather than relying on an estimated marginal rate.

Consent, Documentation, and Disputes

Both parents should agree on Section 7 expenses before they are incurred. A parent who unilaterally enrols a child in an expensive program and then bills the other parent for their proportional share may face resistance — courts routinely scrutinize whether the non-paying parent consented or had reasonable notice. Where parents cannot agree, either party can apply to the court for an order that the expense be shared.

Documentation matters. The parent claiming a Section 7 expense should retain receipts, invoices, and proof of payment. At tax time, the actual childcare tax benefit may differ from any estimates used during the year for interim billing. An annual reconciliation — comparing estimated splits to actual tax outcomes — is good practice and is sometimes required by court order or separation agreement.

Common Mistakes to Avoid

Several errors recur in Section 7 disputes. The most frequent is claiming ordinary expenses — food, clothing, school supplies, basic haircuts — as Section 7 on top of the table amount. These are covered by base child support and are not eligible for separate sharing. Splitting the gross cost instead of the net cost is another common error: failing to subtract tax benefits before dividing the expense inflates both parents' shares.

Many parents also assume the split is always 50/50. It is not — it is proportional to income, and at typical income gaps the higher earner's share is often 60 to 70 percent. Forgetting that spousal support shifts the ratio is another source of error: if spousal support changes (on variation or review), the S.7 percentages change with it. Finally, claiming childcare when the parent is available to provide care during their parenting time may not survive scrutiny — the expense must be necessary because the parent is working, in school, or unable to provide care.