All cash contributions have to be documented, according to the IRS in this publication.
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/publications/p526">https://www.irs.gov/publications/p526</a>
"Cash Contributions
"Cash contributions include those paid by cash, check, electronic funds transfer, debit card, credit card, or payroll deduction.
"You can't deduct a cash contribution, regardless of the amount, unless you keep one of the following.
A bank record that shows the name of the qualified organization, the date of the contribution, and the amount of the contribution. Bank records may include:
A canceled check,
A bank or credit union statement, or
A credit card statement.
A receipt (or a letter or other written communication) from the qualified organization showing the name of the organization, the date of the contribution, and the amount of the contribution.
The payroll deduction records described next.
