I retired from my own business in Nov. 2015. My sales were reported on Schedule C of my 2015 tax return. In my business, I made sales on an installment/payment plan. Therefore I continued to collect money off of 2015 sales into 2016. Some of those payments were made on credit cards, so I received a 1099-K. Did I pay tax on the sales in 2015 or do I pay tax on the money received for those sales in 2016?
