All deductions must be claimed in the year you actually pay the expense. Charitable contributions must be claimed in the year you make the donation. If the donation is very large, it may not all be allowed in that year, and the remainder can be carried forward. It is not allowable to claim past donations as a current deduction. You are not allowed to take the standard deduction and also stack your donations to claim them all at once when it is worth it. The standard deduction exists so that you get something when your itemized deductions are not large enough,you can’t stack itemized deductions and save them for the future.
