One more follow up -
I already had net losses for the tax years 2014 and 2015. Do I still need to create the 1040X for those years? So, my net loss carryback from 2019 would show $0 used in 2014 (no net changes on the 1040X), $0 used in 2015, and then some used for 2016 to 2018 until it is used up?
since 2014 and 2015 are NOL years I would not file form 1040-X for either year (no refund/ no tax due)
If you choose to file an amended return to claim a refund based on a net operating loss, you must file an amended return for the tax year to which you are carrying back a net operating loss. Write or type “Carryback Claim” at the top of page 1 of Form 1040-X.
Attach a computation of your NOL using Schedule A (Form 1045) and a computation of any NOL carryover using Schedule B (Form 1045). Generally, interest won’t be paid on any NOL refund shown on
an amended return processed within 45 days of receipt. For details, see Pub. 536, Net Operating Losses (NOLs)
use the schedules from the 2019 form 1045
https://www.irs.gov/pub/irs-prior/f1045--2019.pdf
schedule A and B of form 1045 can handle 3 years therefore on the 1045 schedule B for the 2016 return show that 2014 and 2015 were NOL years.
for the 2017 year you also include a copy of 1045 schedule B for 2016.
to confirm the timeline, I would have the 3 years from the due date of the 2019 tax return to file these 1040X documents, right?
not exactly!
Generally, for a credit or refund, you must file Form 1040-X within 3 years (including extensions) after the date you filed your original return or within 2 years after the date you paid the tax, whichever is later. If you filed your original return early (for example, March 1 for a calendar year return), your return is considered filed on the due date (generally April 15). However, if you had an extension to file but you filed earlier and we received it on July 1, your return is considered filed on July 1.
If I'm manually completing the form 1040X's, I enter the appropriate tax year at the top and check the box on line 1 (which, presumably, allows me to modify a tax year after the 3 year window has expired), correct? Is there anything to say the changes are due to a 2019 loss carryback (as opposed to 2018 or 2020)?
the line 1 check box merely tells the IRS that there is an NOL c/b
see the instructions provided above
for more info
https://www.irs.gov/pub/irs-pdf/i1040x.pdf
