cost basis

[Shingle]

My brockage 1099-B shows not on file for cost basis for 1100 shares that where sold 0n 5/20/21. Turbo tax is asking for a cost basis for these shares. 

[ColeenD3 · Accepted solution]

It is your responsibility to know how much you paid when you purchased your stock. You can look back at brokerage statements. If you can't determine the basis, it defaults to zero.