I recently made a donation to a tzedaka organization using their online website. I accidentally clicked submit more than once and was charged on my credit card more times than I had wanted to be. I don’t want to ask the organization for a refund, but am I able to count the extra tzedaka given as maaser for future money earned?
For example, I had meant to donate $15 but instead was charged $30. When I earn $150, can I count the $15 maaser as already having been given?
Yes, Maaser may be preempted, this is as if you are giving your maaser fund a “loan”.
Pischei Teshuva beginning of Y:D 249.