They paid me last year for a New Years Eve performance I did in 2015 (which I declared in 2016)...
... then they sent me another check in 2017 for another performance I did for them again in 2016...
... but then they sent me a 1099-MISC for BOTH performances.
I've already declared the first amount in a previous return.
How do I account for the missing amount if I use the 1099-MISC?
Do I just ignore the 1099-MISC, and just declare the latest income?
No don't ignore it. You can enter the 2015 amount as a misc other expense and call something like Reported on prior year return.
Wait... Are you saying, Enter the 2015 "Income" as an "Expense"?
You enter the whole 1099Misc as income then offset it with the misc expense entry.
Wait... I miss spoke (or wrote)... The amount was actually for the NEXT return (one payment for 2015-16 performance, then the other for 2016-17 performance). Meaning, the second check will not be reported until the next return (because I never saw the money until 2017)! Same deal?
I'll just switch the verbiage from "Last Year's Return" to "Next Year's"... Right?