@Zethria1
if you are not issued a 1099-K, there is no reporting requirement if you sold personal items for less than their original purchase price. It is not reportable income. It is a personal loss.
But if a 1099-K is issued, then the 1099-k must be reported as income and then where the sales price was less than the purchase price can be subtracted on Schedule 1, line 24z as an adjustment to income.
