Are these links below still appropriate for reporting undetermined term transactions for non-covered tax lots? ....and what if I don't know whether its short term or long term? What's missing on these items on my 1099-B is purchase date and cost :(
thanks much!
Yes, these are still good.
I suspect that your transactions are long-term since the brokerage companies have been required to keep track and report basis and terms for several years now. And if they do not have this information (unless you moved the securities from one brokerage to another and didn't provide them with that information), the purchase was probably made more than a year ago.
As for the cost basis, if you do not know it, you will have to come up with your best reasonable estimate of the date the securities were purchased. Then use one of the sites where you can look up a historical price of the stock, multiply by the number of shares, and arrive to the cost basis. For example, this website.