Line 30400 on the Canadian federal income tax return is the Amount for an Eligible Dependant, a non-refundable credit for people who are single, separated, divorced, or widowed and who supported a relative living with them during the year. For 2026, the credit base is up to $16,452, which works out to a federal tax reduction of about $2,468.
How the Credit Works
Because Line 30400 is non-refundable, it can reduce your federal tax to zero but won’t produce a refund on its own. If you don’t have enough tax payable to absorb it, the unused portion is lost. The actual reduction is 15 percent of the credit base, so a full claim of $16,452 saves roughly $2,468 in federal tax.1Canada Revenue Agency. T4032 Payroll Deductions Tables – General Information
Your dependant’s own net income reduces the base dollar for dollar. If they earned $5,000 during the year, the base drops to $11,452 and the credit falls to about $1,718. Once the dependant’s net income reaches the basic personal amount, the credit reaches zero.
Who Can Claim It
You can claim Line 30400 if, at some point during the year, all of these were true:
- You were single, divorced, separated, or widowed. If you had a spouse or common-law partner but were not living with them, not supporting them, and not being supported by them, the CRA treats you as separated for this purpose.
- You financially supported the dependant.
- The dependant lived with you in a home you maintained, generally in Canada.
You can’t claim this credit and the spousal or common-law partner amount on Line 30300 in the same year. Only one person per household can claim the eligible dependant amount, even if more than one dependant lives there. If two people in the home both qualify and cannot agree on who claims it, neither one can.2Canada Revenue Agency. Line 30400 – Amount for an Eligible Dependant
Who Counts as an Eligible Dependant
The dependant must be related to you by blood, marriage, common-law partnership, or adoption, and must have lived with you when you supported them. Two groups qualify:
- Parents and grandparents, with no age limit, but they must have been living in Canada.
- Children, grandchildren, brothers, or sisters under 18 at the time you supported them. The age limit is waived if the person has a physical or mental impairment.
Your own child is the one exception to the Canada-residency requirement: they still had to live with you, but not necessarily in Canada. This matters for deemed residents posted abroad, including members of the Canadian Armed Forces.3Canada Revenue Agency. Line 30400 – Can You Claim an Amount for an Eligible Dependant
Child Support and Shared Custody
This is where separated parents get tripped up. If you pay child support for a child under a court order or written agreement, you generally cannot claim Line 30400 for that child. The receiving parent is the one who may be eligible.4Canada Revenue Agency. Child Custody and the Amount for an Eligible Dependant
Two exceptions exist. First, in the year you separate due to a relationship breakdown, you can choose either to claim the eligible dependant amount or to deduct your support payments on Line 22000, whichever gives you the better result. You can’t do both. Second, if a court order or agreement requires both parents to pay child support, neither parent can normally claim the credit, but the two of you can agree that one of you will. Without agreement, neither claims it.
One point the CRA emphasizes: the fact that both parents’ incomes were used to calculate support under the Federal Child Support Guidelines does not make both parents “required to pay.” Unless the order or agreement explicitly requires payments from each side, only one parent is the payer, and only that parent is blocked from Line 30400.4Canada Revenue Agency. Child Custody and the Amount for an Eligible Dependant
Extra Credit if Your Dependant Has an Impairment
When your eligible dependant has a physical or mental impairment, you may qualify for an additional Canada caregiver amount on top of Line 30400. Using 2025 figures, which are indexed annually:
- For a dependant under 18, you can claim $2,687 on Line 30500.
- For a dependant 18 or older, you can claim up to $8,601 on Line 30425, reduced by the dependant’s net income above a threshold.
The under-18 supplement effectively raises the income point at which the combined credits phase out.5Canada Revenue Agency. Canada Caregiver Credit
How to Calculate and File
The math happens on Schedule 5, Amounts for Spouse or Common-Law Partner and Dependants. You’ll need the dependant’s Social Insurance Number and their net income from Line 23600 of their return, or an estimate if they didn’t file.6Canada Revenue Agency. Line 23600 – Net Income The steps:
- Start with the base amount ($16,452 for 2026).
- Subtract the dependant’s net income.
- If the result is positive, that’s your credit base. Multiplied by 15 percent, it becomes your federal tax reduction.
- Enter the credit base on Line 30400 of your return.
NETFILE-certified tax software runs Schedule 5 and drops the result onto Line 30400 for you. Paper filers complete Schedule 5 by hand.7Canada Revenue Agency. 5000-S5 Schedule 5 – Amounts for Spouse or Common-Law Partner and Dependants
The Matching Provincial Credit
Claiming Line 30400 also entitles you to a corresponding provincial or territorial non-refundable credit on Line 58160 of your provincial Form 428. Amounts and thresholds vary by province, and most tax software applies it automatically once the federal claim is in.2Canada Revenue Agency. Line 30400 – Amount for an Eligible Dependant
Keep Your Records
Hold on to supporting documents for at least six years after filing: proof of your relationship to the dependant, their income records, and any custody or support paperwork.8Canada Revenue Agency. How Long Should You Keep Your Income Tax Records The CRA sometimes follows up after processing to validate the claim. You may be asked for documents confirming the dependant’s age, your relationship, or, if you claimed the credit for an adult with an impairment, a medical practitioner’s certificate. Answering these requests on time keeps the credit from being disallowed and your return from being reassessed.9Canada Revenue Agency. Validating Your Eligibility for Benefits and Credits