Donations may or may not be tax deductible, it depends on the tax status of the beneficiary entity.
Donations to personal causes (individuals) are not tax deductible.
Donations to charities may or may not be tax deductible, depending on the DGR (Deductible Gift Recipient) status of the beneficiary charity.
Most charities on mycause have DGR status.
mycause will issue tax or non-tax receipts according to the beneficiary's tax status.