How do I input my total cost basis with a blank box 1e? I tried "I need to adjust my total cost basis" but the number was added to box 1d instead of subtracting.

[tcssimba]

Let's say my proceeds (box 1d) are $150 and my total cost basis (box 1e) is $300. Instead of saying I took a loss of $150, it's saying I made $450. I did try to input it as negative number, but I'm sure that the IRS would have some questions for me.

[ThomasM125]

You may have made an entry to adjust your reported cost basis and that is affecting your gain or loss.

You can adjust your cost basis because it was reported wrong on your form 1099-B. If so, you will see a screen after you enter your investment sale information that says Select any less common adjustments that apply, on which page you will select The cost basis on my statement in incorrect and then be instructed to enter the correct cost basis.

The entry you make there will become your new cost basis and the difference between that amount and your original cost basis will be entered on your form Schedule D Capital Gains and Losses. Your gain or loss will then be the difference between your proceeds and the new cost basis that you entered.

[fanfare]

Your concern about IRS applies whether you adjust your basis Up or Down.

If the basis is not reported, enter the correct basis and use Box B or E.

[tcssimba]

How do I calculate the cost basis when I'm putting in multiple sales of btc? I followed the steps you gave (thank you for that) but I'm at a loss when it comes to the calculating. Do I have to divide my total cost basis by...something? I don't know.

[ErnieS0]

Match up your sales with the appropriate Bitcoin you used @tcssimba. If you made one BTC purchase and had multiple sales from the one purchase, then you would divide the amount of BTC sold by the total purchase.

For example if you bought .25 BTC for $2,500 (including transaction fees) and made five sales of .05 BTC then the cost basis would be (.05/.25) x $2,500 or $500 per sale.

If you made multiple purchases and sales, you can decide what purchases you sold. It doesn't have to be the earliest. You can also use average basis.

See Special Rules for Mutual Funds. The IRS generally treats crypto sales similar to mutual fund sales.