1099-B Undetermined Term Transactions for Non-covered Tax Lots

[Mars1]

I have a client who has sales showing under Undetermined Term Transactions for Non-covered Tax Lots.  How is this supposed to be entered on Form 8949 when client has no idea of his cost and says he may have just bought something using cash?  The date acquired shows N/A, which could be various.

[Just-Lisa-Now-]

If he has no records for basis, then you use zero...maybe the brokerage can help him track down at least a date when it was bought and you can use one of the online historical stock price websites to find out what it was selling for at that time.

[Mars1]

Thank you.  That was my thought but I was still unsure.