A company I did work for in 2019 was sent an invoice in December of that year. However, they paid the invoice in January 2020. I did not file my taxes until April 2020 for 2019 and closed out all of my invoices for 2019 and paid taxes on that income. Also at the end of 2019, I closed my business and started a full time position. Since I already paid taxes on the nonemployee compensation because it was a 2019 invoice, how do I handle the 1099-NEC that I received for 2020?