If someone runs a Gmach that has money that belongs to other people (all the money has to be returned eventually). What principles could there be with regard to someone’s check bouncing? What kinda of limitations are there with regard to contacting him about making the payment?
Essentially the prohibition of “Lo t’hiyei alav k’noshe”, not to pressure someone to pay back a loan, only applies when the person doesn’t have any money, merchandise, objects or assets with what to pay. Therefore it is not very common to run into this issur, unless the person is really so poor or if the loan was indeed very large,and he doesn’t have that amount of assets. Additionally there are those who say that if the person can take another loan from a different gemach that it is as if he does have from where to pay.
You can find these and other halachos regarding this prohibition in “Mitzvas H’chesed” (R. Rosner) in perek 10.
Shulchan Aruch Horav- Hilchos Halva’ah- 2,3, Mishptei Hatorah (R. Spitz) 2-40.