https://turbotax.intuit.ca/tips/filing-coupled-taxes-in-canada-450#:~:text=Unlike%20in%20other%20countries%20such,are%20married%20to%20%2F%20living%20with.
Let’s first set the record straight about the requirements that the Canada Revenue Agency (CRA) has in place for married or common-law Canadians as they file their personal income tax returns.
FACTS
Unlike in other countries such as the United States, Canadian tax rules do not allow spouses or common-laws to file joint income tax returns. Each Canadian files their own tax return and indicates their marital status on the return, and who they are married to / living with.
You do not get to decide whether to claim your marital status on our tax return. Once you are married, you must include your spouse. Once you are common-law, to be considered common-law, two people must live together in a conjugal relationship for 12 months or immediately if you have a child, then you must file as common-law.
The CRA knows your true marital status based on information you file, credits and deductions you apply for, and based on other information that is sent in which relates to you.
Since your marital status has a significant impact on your return – family incomes are combined for calculating income-tested benefits, such as the GST/HST credit or the Canada Child Benefit.
Couples benefit from combining charitable donations and medical expenses.
NOTE: If you receive benefits you are not entitled to because of an incorrect marital status, you will be asked to repay them, with penalty and interest.
Failing to indicate the correct marital status is tax fraud.
Filing as Married
If you were married or in a common-law relationship in the tax year for which you are filing, you must note your status as in the “information about you” section of your tax return, including information about your spouse – their name, social insurance number, net income and employment status. Your tax preparation software may include an option to prepare a ‘coupled’ return, which means you enter the information for you and your spouse together but you file separately once you have completed your tax return. By using this method, the software maximizes the benefits for the couple as a whole while still generating two separate returns. If your spouse claims credits, such as the CCB, or GST/HST, or if they owe any payments, you must report that as well.