If you do not know your spouse's net income, you'll need to make a close estimate and include it on your own tax return. Try to estimate this income as closely as possible as many credits and benefits are calculating using the income of both spouses (combined income) and an incorrect estimate can affect these as well as your tax refund.
- TurboTax Blog -
How do my spouse and I know what our combined net income is if the other person hasn’t done their tax return yet?
https://turbotax.community.intuit.ca/community/other-income/help/how-do-my-spouse-and-i-know-what-our-combined-net-income-is-if-the-other-person-hasn-t-done-their/00/873730