Bought stock in 2021 for 40K. Sold in 2023 for 37K. Imported 1099B stated 0 cost. Can I just manually enter 1099B with cost, and will IRS question the discrepancy?

[taxpayer2301]

Both paper and import from clearinghouse show zero cost. I have monthly statement from brokerage sale that shows cost of 40K as proof.  Does that need to be submitted somehow, or does IRS just take my word for it, differing from what the clearinghouse said (zero cost)?

[DoninGA]

Enter your cost as shown on your statement.  You do not include that statement with your tax return.  Just make sure you keep all your paperwork in a safe place for easy recovery just in case the IRS ever questions the sale.

[fanfare]

For non-covered securities ( BOX B or E) showing zero (wrong) basis, enter the correct basis yourself.
Use code "B" and put -0- in col (g).

For Box A or D, leave basis as reported, use Code "B" and put an adjustment in col(g)

@taxpayer2301