Joint returns
You must compute and use the combined New York City taxable income of both spouses:
If both spouses were city residents for all of 2023, use the amount from line 47 of Form IT-201.
If both spouses were part-year city residents in 2023, use the amount from Form IT-360.1, line 47. (If each spouse was required to complete a separate Form IT-360.1, combine the line 47 amounts from both forms.)
If only one spouse was a city resident for all of 2023, use a separate sheet of paper to compute the New York City taxable income of the full-year city resident spouse as if they had filed a separate federal return. If the other spouse was a part-year city resident in 2023, add the amount of their New York City taxable income (from Form IT-360.1, line 47) to the result.