Attribution rules and using CRA Auto-Fill for shared returns

When couples or family members share investments or property, dividing the resulting income or capital gains can get complicated. Even more so if you are relying on CRA’s Auto-Fill My Return tool, which pulls tax slips into one person’s return automatically.

The CRA’s attribution rules may require income to be taxed in someone else’s hands—regardless of who is listed on the account or the slip. Understanding these rules and how they interact with Auto-Fill is essential to file shared returns accurately.

What Are the Attribution Rules?

Attribution rules are CRA provisions that prevent income splitting between family members purely for tax advantages. If one person gives money or assets to a spouse, common-law partner, or minor child, any investment income earned from those funds may be attributed back to the person who provided the funds.

Attribution applies when:

• A high-income spouse gives or loans funds to a lower-income spouse to invest

• A parent contributes capital to an account in a minor child’s name

• Assets or investments are transferred into a joint account without proper documentation or sharing of ownership

Attribution applies to:

• Interest income

• Dividends

• Rental income

It generally does not apply to capital gains, unless the attribution arises from a trust or specific structured transfer.

How Attribution Affects Reporting Shared Income

If attribution rules apply, the income must be reported by the contributor, not the person who holds the account or receives the T-slip.

Examples:

• A husband transfers $50,000 into a joint investment account with his wife. All interest and dividend income must be reported by him, unless the wife contributed equal capital.

• A parent opens a GIC in a child’s name but provides all the funds. The parent reports all the income, even if the slip is in the child’s name.

Using Auto-Fill My Return for Joint Investments

CRA’s Auto-Fill My Return feature automatically imports T3, T5, and other slips into your return based on your SIN number. But it does not know who actually earned the income.

When using Auto-Fill:

• Do not assume the slip is yours to report fully just because it appears in your account

• Check each slip carefully and compare it to your records of account contributions

• Adjust for shared ownership by claiming your portion of income and deducting the other’s on line 23200 (Other deductions)

• The other person must manually add their share of the income on their return

This is especially important for slips from joint investment accounts or family trust distributions.

Auto-Fill Can Mislead If You Rely on It Blindly

Auto-Fill My Return is a convenience, not a compliance guarantee. If your return is audited, the CRA will expect you to explain how you allocated income, even if Auto-Fill populated the slip automatically. You are still responsible for making adjustments in line with ownership and attribution rules, not system defaults.

To stay compliant:

• Compare every slip against your investment ownership records

• Document all adjustments made and why

• Keep written proof of who funded each investment, including transfer records and contribution notes

How to Stay Accurate with Shared Returns

Here are best practices to avoid misreporting shared income when attribution rules apply:

• Establish and document ownership when opening joint accounts

  • Use contribution logs or formal agreements to show who funded what

• Review all slips that appear in Auto-Fill

  • Confirm if each slip applies to you, your spouse, or needs to be divided

• Adjust split slips accordingly

  • Deduct another person’s share on line 23200 if needed

• Retain all documentation

  • Keep for at least six years in case CRA requests evidence