Why is it asking for 2021 net income?

As per the Canada Revenue Agency (CRA) Line 23600 – Net income Your net income is used to calculate federal and provincial or territorial non-refundable tax credits.

The CRA also uses your net income, and your spouse's or common-law partner's net income if you are married or living common-law, to calculate amounts such as the Canada child benefit, GST/HST credit, social benefits repayment, and certain other credits.

Enter your spouse's or common-law partner's net income on page 1 of your return under "Information about your spouse or common-law partner," if this applies to you. Report their net income, even if it is zero.

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