You need to check yoru tax summary...
1) If your "Taxable" income was already reduced to zero by all the other prior "itemized" deductions, then even a billion $$ more of donations would not change anything.
2) if you have net self-employed income, the extra donations do not reduce yoru SE tax (SS and Medicare)
____________________________
IF using Desktop software, switch to Forms mode and check your $$ deductions totals on the Schedule A, and then your 1040, line 15 to see if yoru taxable income is already at a zero.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
