for SSTBs you check yes for non SSTBs you leave that blank.
the thing with SSTBs is you have to look at the QBI component worksheet for schedule C because there is a special computation to compute the QBI for SSTBs (it differs from the QBI computation for non-SSTBs). in any event QBI losses (whether SSTB or not) will only reduce QBI income to zero. there cannot be a negative QBI amount on line 13 of 1040
as far as i can tell Turbotax correctly computes the QBI deduction or QBI loss carryforward if proper entries are made. QBI income or loss it's not the schedule c income or loss but at most 20% of the income or loss. then because you have an SSTB or taxable income is too high the QBI income loss c/o could even be zero.
I don’t have income on Sch C, only expense which are losses.
If I answer YES to SSTB (just for concept) yes you do
Q: Does Sch C loss, produces a SSTB loss so in the it reduces QBI by that amount? Lets say I have Sch C loss of $1000 so it will reduces QBI by this amount? that depends on your taxable income (including capital gains and qualified dividends) because if it's too high your schedule C loss produces no QBI loss (due to it being an SSTB). if it isn't and you have QBI income from other trades or business that QBI loss from schedule C will offset it. Any excess loss becomes a carryover Also, income from MLPs that are not SSTBs and certain REIT dividends (line 5 of 1099- DIV) generate a 20% QBI deduction. this amount combined with any other qbi deduction can't exceed 20% of taxable income after reduction for long-term capital gains and qualified dividends
you really need to study the 8995/8995-A and the QBI component worksheets for each trade or business.
It's complicated tax law
