You need to do the best efforts of finding your basis. If you can't provide a basis, the IRS assumes no cost so do your best efforts in recreating the basis, always err on the conservative side.
Often the company has a website that would help. There are also many stock cost basis calculators on the internet that you can search for.
Your basis would have been the amount you paid plus fees for the stock plus any dividend reinvestments you possibly made over the years, adjustments for stock splits and corporate actions.
If the stock was received in an inheritance, you got the FMV at 12/31 of the year of death. If it was a gift you got the original holders cost basis (unless at time of gift it was a loss, then you got the FMV on date of gift this is to avoid transferring losses to higher income tax returns).
If the amount is deminimis, you can just enter $0 as the cost basis and see the impact to your return..
If you do not report it , the IRS does get a copy and will bill you plus interest and penalties for the full proceeds and assumes $0 basis.
I wish you luck and hope this answer was helpful?
**I don't work for TT. Just trying to help. All the best.
***Say "Thanks" by marking as BEST ANSWER and clicking the thumb icon in a post and that I solved your question
**Mark the post that answers your question by clicking on "Mark as Best Answer" I am NOT an expert and you should confirm with a tax expert.
