TL;DR: Broker issued a 1099 listing the SSN of taxpayer A who did not, for tax purposes, own the money in the brokerage account. The money belonged to taxpayer B. How can taxpayer B file his 1040 claiming the capital gains listed on the 1099 while at the same time ensuring taxpayer A is not assessed taxes from the 1099?
Actual scenario: In anticipation of lending my mother money to buy a house I transferred cash into a new brokerage account in her name under her SSN. However I had full management authority of "her" brokerage account. While the money was in her account I actively invested it, accumulating significant short-term capital gains. She decided not to buy a house and so I sold the stocks and transferred the cash back into an account in my name. (I.e., we did not end up establishing a loan from me to her.)
The broker must report capital gains (Form 1099-B) accumulated while the money was in my mother's account under her SSN. How can the 1099s be attributed to me when we file our individual tax returns?
We each file as Head of Household. Because of our relative tax situations this year it will be much more efficient if the gains can be attributed to me for tax purposes. (In fact, I imagine that an auditor examining the situation would argue that the titling of the funds under my mother's name should be disregarded for tax purposes because: no loan was actually made, I retained control over the funds, the transfer was reversed, and no real benefit accrued to my mother.)
