I own a small reselling business which operates mainly on Amazon. I filed my own taxes for the business for the year 2019 and just received a proposed change, since I neglected to include form 1099-K provided to me by Amazon. I'm positive I don't owe the amount they proposed I do, so I'm putting together documentation to prove I don't. My issue is purchases I made throughout the year. I have all paper receipts from stores I purchased inventory from, but I'm not sure if I should just send all the receipts in, or take pictures of them/scan them, or something else. Is there a more streamlined way to show all my purchases so I can deduct them from the gross transactions on the 1099-K?