When you donate, the DGR will usually issue you with a receipt, but they don't have to. Learn how to lower your income tax while supporting charity.Discover essential tips for tax season and try our donation tax calculator. For a donation to be tax deductible, it must be made to an organisation endorsed as a deductible gift recipient (DGR). It must also be a genuine gift. Tax deductible donations give your refund a boost. How much in donations can I claim on tax without receipts? You can only claim a tax deduction for gifts or donations to organisations which are deductible gift recipients (DGRs). You can claim 33.33 cents for every dollar you donated to charities and organisations on the approved donee organisations list.