You can use the NOL carry back by submitting form 1045. You do not also have to complete a form 1040X. File one or the other.
Individuals may use Form 1045 to claim a quick refund resulting from the carryback of an NOL. Form 1045 must be filed on or after the date for filing a tax return for the NOL year (2016). Form 1045 and the instructions can be downloaded from www.irs.gov. See https://www.irs.gov/publications/p536/ar02.html
If you do not file a Form 1045, you will submit a Form 1040X to process the NOL. If you file a 1040X instead of a Form 1045, you still must attach the NOL computations using the Form 1045 computation schedules.
If you choose to file a Form 1040 X, the net operating loss carryback is reported on line 1 and the box for Net Operating Loss Carry Back should be checked.
