Unknown acquisition date and cost basis entry on sale of stock - how is this entered?

[mrppcox]

The fields will not accept "Unknown."

[Critter]

For the purchase date you can us the word Various however you must enter a cost basis amount ...if the broker didn't have the information then you will need to figure it out.  If you don't know it then enter a zero and all of the sale is 100% taxable. 

[jwzat]

In the case mentioned (unknown purchase date and cost basis), what do you select for "Sale Category" in TTax Premier? "Long term not covered"? "Long term not reported"? My brokerage statement doesn't state which to use. Thx