The United Way, the umbrella agency that receives the donations and then forwards to the various organizations, does take a small percentage (I don't know exactly what it is, but it's not large) as a clearinghouse sort of processing fee. I used to work for a non-profit who received donations the same way. So if you wanted to donate directly to the charity, they would get a little more because that processing fee isn't taken out. However, donating a lump sum can be a strain on the budget, depending on your circumstances. A few bucks taken out of my paycheck each payday is hardly noticed.