Our son spent alternate weeks with each of us. We both bought groceries, washed school clothes and received a shared-custody CCB payment. I thought we would simply alternate the eligible-dependant credit as well.
Then I read the support paragraph in our order. It required me to pay his mother. Her income helped determine the amount, but that did not necessarily mean she had a legal obligation to pay me.
Establish eligibility before choosing a claimant
The federal amount for an eligible dependant, line 30400, is a non-refundable tax credit. It is not the CCB. A claim generally requires an eligible dependant you supported who lived with you in a home you maintained, the required marital circumstances, and a dependant income below the applicable limit. The CRA also restricts competing spouse/dependant claims and allows only one such claim per household. Full line 30400 conditions.
For a child, check the age or impairment conditions too. Paying school expenses or receiving CCB does not by itself establish eligibility. Use Schedule 5 for the actual calculation instead of assuming the headline personal amount is a cash refund.
Read who is legally required to pay support
The ordinary rule prevents a parent required to pay child support from claiming this amount for that child. Shared parenting time does not automatically remove that restriction.
The CRA distinguishes two situations:
- Only one parent is required to pay. That payer generally cannot claim the credit for the child. The recipient may qualify if the other conditions are met.
- Both parents have clearly established payment obligations under the order or written agreement. One may be able to claim if they agree who will do so and the other conditions are met. Without agreement, neither can claim.
Both incomes being used in a support calculation does not prove that both parents must pay. Nor does calling a calculation a “set-off” resolve what the order actually requires. CRA's shared-custody support examples.
Apply the distinction to one ordinary year
Suppose our order requires only me to pay $300 each month, our son lives with each parent half the time, and that arrangement lasts all year. My payment obligation generally prevents my line 30400 claim for him. An agreement between us to alternate tax years does not erase that obstacle.
If the actual order instead clearly requires each parent to pay support, the mutual-obligation rule needs review. It still does not let us split one credit into two half claims. Keep the order and the agreement about the claimant with the tax records; do not rewrite the legal meaning to obtain a preferred tax result.
Review a year when circumstances change
The year of separation or a change of custody can produce different rules. For example, where each parent becomes required to pay support at different points in the year, the CRA requires agreement about which otherwise eligible person claims. A separate part-year separation rule can involve choosing a personal credit instead of deducting support. These cases need the dates and the full return, not just the December parenting schedule. Support and personal-credit rules.
The lunch-making still happens in both homes. For the tax return, I keep the care schedule, support obligation and claimant decision as three separate questions.
Checked October 20, 2026, against the CRA's current federal guidance.
