Where do I deduct credit card rewards?

If you have a 1099-K, then you must have some self-employment/business income. 

Credit Card Rewards are not taxable, so you do not need to input them in TurboTax.  Since they are included in your 1099-K as income then you need to subtract them out of the net profits as an expense.

 

If you are reporting your 1099-K on Schedule C, then you can enter an expense on the Schedule C as a reduction of costs.

 

For additional information refer to the following link:

Credit card rewards treatment

Thank you, in which expense section can I deduct them? I have entered other expenses into "supplies" (cost of my shipping boxes), "office expenses" (cost of shipping and ink), and "miscellaneous expenses" (PayPal fees). None of the expense categories seem to mention credit card rewards, only credit card fees/interest. Would this just fall under "miscellaneous expenses"?

You would include it under miscellaneous expenses and describe the nontaxable reward.