I donated $200 to a charitable organization and they gave me papers to file for taxes saying I did. I already filed my taxes. Is there anything I can do?

[fanfare]

$200 charitable contribution made in 2021 is deductible on your 2021 tax return.

[Carl]

If you've already taken the $300 "above the line" charity deduction ($600 if MFJ), then I seriously doubt claiming another $200 on SCH A will have any impact on  your tax liability. Until the total of all your itemized deductions exceed your standard deduction, thay have no impact.

If you have not take the "above the line" deduction, then the $200 "might" reduce your tax liability by $5-10 if you're lucky. You'll have to decide if it's worthwhile to amend for that.