Get your taxes done using TurboTax

As stated, a negative income amount on Form 1040 indicates a possible business NOL. 

NOL is BASICALLY Form 1040 line line 9 offset by line 8. 

So if line 9 shows 10,000 (income) and line 8 shows -15,000 (loss) the NOL would be 5,000

This also COULD be adjusted for certain "disallowed deductions" as explained in Pub 536, but that's pretty close to it.

Please see worksheet 1 in Pub 536

TO CLAIM THE NOL NEXT YEAR

In TurboTax, under the Business tab

Scroll down to "Less Common Business Situations"

Scroll down to "Net Operating Loss/QBI Carryforward Loss     START

Check to see if anything was generated from the previous year, if not, enter the NOL here. 

Enter the loss as a positive number. 

Enter the full amount of the carryover even if all of it can't be used

If the loss is still not completely used, you'll need to again check this same screen the following year until the loss is depleted. 

When you claim NOL, it is listed on Schedule 1 line 8a