How do I file ESPP sales on my tax return?
Your basis in the shares you sold is the discounted amount you purchased it for at each pay period. The tax law does not permit averaging. Unfortunately, the record keeping can be onerous when several years are involved. Then, the basis for the portion of the shares you sold is determined on a “first-in-first-out” method. That is, the first shares you bought, are the first ones you sold. I am a tax professional and this is even complicated for me when I prepare my own return. But once you get all the numbers in front of you, inputting into the software should be relatively easy, but time consuming. Good luck!