Next. I downloaded 1099 from my broker which included, in addition to Interest and Dividend and Capital Loss also.. carryover losses. From where? I did not have any. My broker insisted that it did not come from them. A specialist suggested to go to the Tools and delete this carryover loss form. Did not do anything. So I went out, tried again and the third time was the charm - it was not there. Still not clear where it came from.
Brokerages don't keep track of that because they can't -- carryover losses are based on the sum of all losses from all sources of losses (I have 3 brokerages - Vanguard, Fidelity, Schwab), so any given brokerage won't know about the losses from the other brokerages. Nor would they know your tax history, i.e. carryover losses depend on the previous year less this year's net gains and losses less the $3,000 regular income thingy ...
The starting carryover loss can only come from your prior year's tax return.
It started with Form 8606, I could not find it. A specialist told me that this year one had to download and mail it separately... What nonsense. I finally found it.
Mail one form in separately? The specialist must have been joking. I have never heard of electronically filing a return that is missing a form, and then snail-mailing in the missing form! I thought it was all or nothing -- either file the whole return electronically, or snail-mail in the ENTIRE tax return.
And yuh, Form 8606 is one of the forms that is part of my tax return every year, sigh.