@Ark808 wrote:
Im not too sure i understand. I was the one that was received the $200k and my sibling is keeping the house.
I apologize because it was I who did not understand (or simply misread your original post).
You are the only who actually made the gift of $300,000 to your sibling since you accepted $200,000 for property that, in fact, had a fair market value of $500,000.
As a result, you would the party that should report the $300,000 gift from you to your sibling on Form 709.
