You may not need a receipt from Goodwill for drop-off donations, if the value is $250 or less and you have maintained written records of the donation that includes:
- The names of the charity
- Date of contribution
- A resonably detailed description of the donated property
- The fair market value of the property at the time of donation.
Please see this site (https://www.irs.gov/uac/newsroom/tips-from-irs-for-year-end-gifts-to-charity) for more information on charitable donations.