Make your individual voluntary contribution on your original tax return. As mentioned above, to claim a charitable donation, you need to itemize your deductions using Form 1040, Schedule A as part of your tax preparation.Learn how to easily create your donation receipts and the best practices to follow in the year-end receipts to your donors. What to include in donor acknowledgment letters? Charitable contributions are generally taxdeductible if you itemize. This handy comprehensive checklist to help nonprofit 501(c)(3) organizations stay up-to-date with annual filing requirements. Having a nonprofit corporation is not the same as being tax-exempt. The charity must still provide the written acknowledgment to the donor. To file to obtain Sales Tax Exemption: Agency: California Department of Tax and Fee Administration. Processing with the IRS generally takes eight to sixteen months, depending on your charitable purpose(s).