No, you do not have to re-file both returns.
Joint account earnings can be split 50/50 or in whichever proportions as the joint account holders agree.
If you report 100% of the capital gains, then your son does not report anything on his tax return.
Your son can write to the IRS stating that all gains have been reported by you.
There should be a primary SSN that the account is associated with, and IRS will match that with whoever's SSN it is. So whoever's return it goes on, or does not go on, make sure 100% is reported to IRS between the two returns. Also due to IRS matching this document, you may get a letter a year or two and may have to explain to them, how it was reported. So keep the tax documents in your tax records for at least 3 years.
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I opened a joint tenancy investment account for investing in stocks with my girlfriend (life partner) in 2021.
If I understand the explanation below correctly; I can have her report all the tax loses to her 1040 ($4700) and I report no loses this year. She would also be able to carry forward $1700 in ST capital loses to 2022. Even though we split the dividend income 50/50.
Would we be able to change the allocation of gains or loses in 2022 and following years? She would still have the $1700 carry forward loss in 2022, so assuming we have gains in 2022, I can report all the gains myself. I would be able the use the standard deduction to offset our taxable stock gains.
In 2020 and many years prior, I was not required to even file a tax return. I live on S.S. and a personal Tax free disability income policy for life. My girlfriend still works making approx. $55K per year.
Do I understand this correctly? Any advice or suggestions much appreciated.
Thank you in advance for your assistance,