@DiddlyD there is no requirement to enter 1099's as such using the Turbotax form. just say you didn't get any then you can enter whatever you like.
the following is from the IRS website and would apply to similar non-income items like security deposits:
If you allow your customers to receive cash back when they use their debit cards for purchases:
If you allow your customers to receive cash back when they use their debit cards for purchases, the Form 1099-K you receive will include those cash back amounts as part of the gross amount of payment card transactions. Generally, you would not include cash back amounts as part of your business's gross receipts on your income tax return, nor would you claim such amount paid to a customer as a business expense. It is important that you maintain records of customer cash back activity over the course of your tax year.
whether the IRS will send you a notice if the k and reported amounts disagree is unknown. at least schedule c has a line for returns and allowances for those that want the amounts to match but the reported amount includes non-income amounts. I wouldn't especially if that amount is large which can be the case
as for Turbotax - probably just a p y a approach since there would be complaints from those who only entered taxable revenue and then got an IRS notice for a mismatch. in other words really a can't win situation
