234 – Business investment loss
As a rule, you can deduct a business investment loss on line 234 if you sustained losses in 2017 on investments (shares or debt securities) in a Canadian-controlled private corporation (that is, a corporation whose shares are not listed on a stock exchange). To calculate the amount you can deduct, complete form TP-232.1-V, Business Investment Loss. Enclose the form with your return.
For more information, consult the guide entitled Capital Gains and Losses (IN-120-V).
On line 233, enter the total losses you sustained. On line 234, enter the amount you can deduct for the losses.
If you were a member of a partnership, the total losses may be shown in box 13 of your RL-15 slip.
If the amount on line 234 is greater than your total income, you can use the excess to reduce your income for the previous three years or for future years. If you wish to use a loss to reduce your income for previous years, complete form TP-1012.A-V, Carry-Back of a Loss, and file it separately from your return.