Yes TurboTax recognizes box 21 of the T3 slip: "This is the full amount of capital gain or loss. Enter a loss as a negative number (e.g. -800). The portion not eligible for the capital gains deduction (the amount in box 21 minus the amount in box 30) is transferred to line 176 on Schedule 3. All or part of this amount may be foreign non-business income, which will be footnoted. The foreign non-business income is transferred to Form FTC, Foreign Tax Credits Worksheet and from there included in your credit on line 433 of Schedule 1."
Quoting from the link below:What if the T3 slip is for a joint investment?
"If the investment reported on your T3 is a joint investment with your spouse or common-law partner, enter your percentage of the investment in the first box. If the shares are 50% each (50-50) then enter 50% in the first box, and do not enter a percentage in the second spouse's slip.
For each box that applies to you, enter the full amount from your T3slip; only your portion is transfered to your return. If you are preparing a coupled return, Your spouse's percentage is automatically filled in.
Note: Although this Income amount does not appear in your spouse's T3 entry window, do not reenter it there . It has been included on his or her Schedule 3 - Capital Gains or Losses, or Schedule 4 - Statement of Investment income."
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