No. All amended returns are done on Form 1040X. 1099K is just one indication of income you got, and the total amount reported on it is added to all other sources - 1099-MISC, Cash, etc - to arrive at your Gross income, before deductions. ALL income sources must be reported; 1099K is just one source. [added] If you have a 2017 1099-K, then it goes on a 2017 return - amended or original. 2017 forms can not go on a 2018 return.
