- You've received a fundraising call from a local frum institution and agree to donate $100. The individual on the phone directs you to the donation site to fill out the forms.
- After you get off the phone, you realize that they're fairly close to their overall goal and so you resolve to donate $200 to hit that big, round number.
- As you're filling out the donation form, you decide to refresh the webpage and see that they're only $160 from their goal, so you refill the form to finalize the donation for $160.
How does halacha consider the additional $40?
Even though you've fulfilled your verbal commitment to the fundraiser, tzedakah in the Talmud is linked to Kodshim vis a vis the impact of intent, where a mental declaration is sufficient to designate an animal for a korban. At the very least, one should be concerned that one's mental intent may constitute a declaration to donate a higher amount as "doing the right thing" (yashrus) if not actually obligatory.
But in this case, the desire to donate the higher amount was for the purpose of reaching a stated goal, and therefore might be considered neder al t'nai - a conditional vow.
Conversely, one might argue that the amount being al t'nai of hitting a certain goal is not the same thing as the donation itself being conditional, and that the process of filling out the donation form itself may constitute a commitment to donate the higher amount, even if you change the number before finalizing the donation.