The only way to take expenses against a 1099-K is to have a business. Since you are collecting donations, you don't have that option.
Please see this answer from Bsch4477.
As the article suggests you could report the 1099-K amount as other income and report the same amount again as a negative amount as other income with the text something like “Offset GoFundMe payments on 1099-K”
1099-K
You can add it as other income and then back it out again with an explanation.
- Wages & Income
- I'll choose what I work on
- Less Common Income select Start (or Update) for
- Miscellaneous Income.
- Other reportable income and you can enter your own description(s) and amount(s).
