OK, Thanks ... I guess that is what I will have to do.
The financial institution will only report the T-slips against the SIN of the joint account primary owner (the first name that appears on the account). I asked.
What they suggested to change this was to open new joint account, with my wife as the primary, and transfer her contributions there. But this switch will trigger gains as far as CRA is concerned. I would have to basically sell everything in the old account (reported under my SIN) and buy it again in the new account (with the new book cost reported for her SIN).
The proportional reporting for joint accounts is a real pain. Turbotax should really allow my situation (entering 0% for me, because CRA has all the T-slips for my SIN), or allow imported slips to be associated with my wife not forcing me to re-enter everything. Turbotax is already handling both returns at the same time, so this is really a missing function.
As a side comment, I have decided to "bite the bullet" and actually open the new joint account for my wife as primary, do the above "rollover dance" and basically do away with proportional income/gain reporting going forward (will have to do it one more time in 2024 because the "rollover" will happen this year). But then I am done for good. Both accounts will be JTWROS so when one spouse dies the other immediately takes over. There is no probate (accounts pass to survivor rather than estate). My wife's contribution go into one account (her primary, me secondary) and mine to the other (me primary, her secondary). No more proportional reporting, and everyones tax slips go to CRA with the correct SIN.
This would seem to work in my case (with spouses), but may not for other joint account arrangements. I am not a legal/ tax professional, so ask someone who can give advice, especially about "bare trust" and "presumptive trust" rules.
